Bevel gear assembly: complete guide to geometry and axial backlash<\/title>\n\n <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin=\"\">\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&display=swap\" rel=\"stylesheet\">\n\n <style>\n *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }\n\n :root {\n --green: #1a6b3c;\n --green-dark: #0f4a28;\n --green-mid: #2d8a55;\n --green-light: #e8f4ed;\n --green-xlight: #f2faf5;\n --amber: #b45309;\n --amber-light: #fef3c7;\n\n --bg: #ffffff;\n --bg-soft: #f8f9fa;\n --bg-muted: #f1f3f5;\n --border: #e5e7eb;\n --border-mid: #d1d5db;\n\n --text-primary: #111827;\n --text-secondary: #4b5563;\n --text-muted: #9ca3af;\n\n --radius-sm: 6px;\n --radius-md: 8px;\n --radius-lg: 12px;\n --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);\n --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);\n }\n\n body { min-height: 100vh; }\n\n .article-page {\n display: flex;\n flex-direction: column;\n min-height: 100vh;\n }\n\n .article-body {\n padding: 40px 28px 64px;\n display: flex;\n align-items: flex-start;\n gap: 36px;\n max-width: 1180px;\n margin: 0 auto;\n width: 100%;\n font-family: 'Inter', sans-serif;\n font-size: 15px;\n letter-spacing: 0.02em;\n color: var(--text-primary);\n }\n\n .article-body__main {\n flex: 1;\n min-width: 0;\n max-width: 820px;\n }\n\n .article__title {\n font-size: 24px;\n font-weight: 700;\n color: var(--text-primary);\n line-height: 1.3;\n margin-bottom: 8px;\n }\n\n .article__subtitle {\n font-size: 15px;\n color: var(--text-secondary);\n line-height: 1.75;\n margin-bottom: 24px;\n }\n\n .article__h2 {\n display: flex;\n align-items: center;\n gap: 9px;\n font-size: 17px;\n font-weight: 600;\n color: var(--text-primary);\n padding-bottom: 10px;\n border-bottom: 1px solid var(--border);\n margin-top: 28px;\n margin-bottom: 14px;\n }\n\n .article__h2-icon {\n display: flex;\n align-items: center;\n color: var(--green);\n }\n\n .article__p {\n font-size: 15px;\n color: var(--text-secondary);\n line-height: 1.8;\n margin-bottom: 14px;\n }\n\n .article__list {\n margin: 0 0 14px 0;\n padding-left: 20px;\n list-style: disc;\n }\n\n .article__list li {\n font-size: 14.5px;\n color: var(--text-secondary);\n line-height: 1.8;\n margin-bottom: 4px;\n }\n\n \/* ============================================================\n CALLOUT BOXES\n ============================================================ *\/\n .infobox {\n background: var(--green-xlight);\n border-left: 3px solid var(--green);\n border-radius: 0 var(--radius-md) var(--radius-md) 0;\n padding: 12px 16px;\n margin: 16px 0;\n }\n\n .infobox__title {\n display: flex;\n align-items: center;\n gap: 6px;\n font-size: 13px;\n font-weight: 600;\n color: var(--green-dark);\n margin-bottom: 5px;\n }\n\n .infobox__text {\n font-size: 13.5px;\n color: var(--green);\n line-height: 1.65;\n }\n\n .infobox--grey {\n background: var(--bg-muted);\n border-left-color: var(--border-mid);\n }\n\n .infobox--grey .infobox__title { color: var(--text-secondary); }\n .infobox--grey .infobox__text { color: var(--text-secondary); }\n\n .warnbox {\n background: var(--amber-light);\n border-left: 3px solid var(--amber);\n border-radius: 0 var(--radius-md) var(--radius-md) 0;\n padding: 12px 16px;\n margin: 16px 0;\n }\n\n .warnbox__title {\n display: flex;\n align-items: center;\n gap: 6px;\n font-size: 13px;\n font-weight: 600;\n color: #92400e;\n margin-bottom: 5px;\n }\n\n .warnbox__text {\n font-size: 13.5px;\n color: var(--amber);\n line-height: 1.65;\n }\n\n \/* ============================================================\n IMAGE\n ============================================================ *\/\n .article__figure {\n margin: 20px 0;\n text-align: center;\n }\n\n .article__figure img {\n max-width: 100%;\n }\n\n .article__figure figcaption {\n font-size: 13px;\n color: var(--text-muted);\n margin-top: 8px;\n }\n\n \/* ============================================================\n TABLE\n ============================================================ *\/\n .article__table-wrap {\n overflow-x: auto;\n margin: 16px 0;\n border-radius: var(--radius-md);\n border: 1px solid var(--border);\n }\n\n .article__table {\n width: 100%;\n border-collapse: collapse;\n font-size: 14px;\n }\n\n .article__table thead {\n background: var(--green);\n }\n\n .article__table th {\n text-align: left;\n font-weight: 600;\n color: #ffffff;\n padding: 10px 14px;\n border-bottom: 1px solid var(--border);\n white-space: nowrap;\n }\n\n .article__table td {\n padding: 10px 14px;\n color: var(--text-secondary);\n border-bottom: 1px solid var(--border);\n line-height: 1.6;\n vertical-align: top;\n }\n\n .article__table tr:last-child td { border-bottom: none; }\n\n .badge {\n display: inline-block;\n font-size: 12px;\n font-weight: 600;\n padding: 2px 8px;\n border-radius: 20px;\n background: var(--green-light);\n color: var(--green-dark);\n }\n\n \/* ============================================================\n RESPONSIVE\n ============================================================ *\/\n @media (max-width: 900px) {\n .article-body { flex-direction: column; padding: 20px 20px 48px; }\n }\n \n \/* Glossary tooltips *\/\n .glossary-term {\n border-bottom: 1px dotted var(--green);\n color: var(--green);\n font-style: italic;\n cursor: help;\n }\n .glossary-tooltip {\n position: fixed;\n z-index: 9999;\n background: #fff;\n border: 1px solid var(--border-mid);\n border-radius: var(--radius-md);\n box-shadow: var(--shadow-md);\n padding: 10px 14px;\n max-width: 300px;\n font-family: 'Inter', sans-serif;\n font-size: 13px;\n }\n .glossary-tooltip__title {\n font-weight: 600;\n color: var(--text-primary);\n margin-bottom: 4px;\n }\n .glossary-tooltip__def {\n font-size: 12.5px;\n color: var(--text-secondary);\n line-height: 1.6;\n }\n .glossary-tooltip__tag {\n display: inline-block;\n margin-top: 6px;\n font-size: 9px;\n font-weight: 600;\n padding: 2px 7px;\n border-radius: 20px;\n background: var(--green-light);\n color: var(--green-dark);\n text-transform: uppercase;\n letter-spacing: 0.04em;\n }\n\n <\/style>\n<\/head>\n<body>\n\n<div id=\"tt-gioco-di-flanchi-backlash\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Backlash<\/div>\n <div class=\"glossary-tooltip__def\">Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-addendum\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Addendum<\/div>\n <div class=\"glossary-tooltip__def\">Tooth height above the pitch circle. For standard tooth geometry, it equals one module.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-dedendum\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Dedendum<\/div>\n <div class=\"glossary-tooltip__def\">Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-poliketone-pk\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Polyketone (PK)<\/div>\n <div class=\"glossary-tooltip__def\">Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n\n <div class=\"article-page\">\n <div class=\"article-body\">\n <div class=\"article-body__main\"><script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@graph\": [\n {\n \"@type\": \"TechArticle\",\n \"@id\": \"#article\",\n \"headline\": \"Bevel gear assembly: complete guide to geometry and axial backlash\",\n \"description\": \"A badly assembled bevel pair doesn't give immediate signals. It works, at first. Then the noise arrives, then wear concentrated on a narrow zone of the tooth, then the failure. In almost all cases, the root is a single one: geometry out of tolerance, misaligned axes or wrong axial backlash.\",\n \"inLanguage\": \"en\",\n \"mentions\": [\n {\n \"@id\": \"#term-gioco-di-flanchi-backlash\"\n },\n {\n \"@id\": \"#term-addendum\"\n },\n {\n \"@id\": \"#term-dedendum\"\n },\n {\n \"@id\": \"#term-poliketone-pk\"\n }\n ]\n },\n {\n \"@type\": \"DefinedTermSet\",\n \"@id\": \"#glossario\",\n \"name\": \"Glossario - Bevel gear assembly: complete guide to geometry and axial backlash\",\n \"hasDefinedTerm\": [\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-gioco-di-flanchi-backlash\",\n \"name\": \"Backlash\",\n \"description\": \"Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-addendum\",\n \"name\": \"Addendum\",\n \"description\": \"Tooth height above the pitch circle. For standard tooth geometry, it equals one module.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-dedendum\",\n \"name\": \"Dedendum\",\n \"description\": \"Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-poliketone-pk\",\n \"name\": \"Polyketone (PK)\",\n \"description\": \"Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.\",\n \"inDefinedTermSet\": \"#glossario\"\n }\n ]\n }\n ]\n}\n<\/script>\n\n\n\n <h1 class=\"article__title\">Bevel gear assembly: complete guide to geometry and axial backlash<\/h1>\n<p class=\"article__subtitle\">A badly assembled bevel pair doesn’t give immediate signals. It works, at first. Then the noise arrives, then wear concentrated on a narrow zone of the tooth, then the failure. In almost all cases, the root is a single one: geometry out of tolerance, misaligned axes or wrong axial <dfn id=\"def-gioco-di-flanchi-backlash\"><span class=\"glossary-term\" data-tooltip=\"tt-gioco-di-flanchi-backlash\" title=\"Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.\">backlash<\/span><\/dfn>.<\/p>\n<h2 class=\"article__h2\" id=\"fundamental-geometric-characteristics\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"m3 20 9-16 9 16H3z\"><\/path><\/svg><\/span>\n Fundamental geometric characteristics\n<\/h2>\n<p class=\"article__p\">Bevel pairs are pairs of gears that change the direction of motion transmission by working at 90\u00b0. Unlike spur gears, the teeth aren’t parallel to the axis: they follow a truncated-cone shape, which allows motion and power to be transferred between intersecting axes.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Parameter<\/th><th>Meaning<\/th><th>Importance in assembly<\/th><\/tr><\/thead>\n<tbody><tr><td>Pitch angle<\/td><td>Angle of the pitch cone relative to the gear axis<\/td><td>Determines the shaft-crossing angle and the correct contact position<\/td><\/tr>\n<tr><td>Module<\/td><td>Base dimension of the tooth and the teeth<\/td><td>Affects strength, dimensions, backlash and load capacity<\/td><\/tr>\n<tr><td>Transmission ratio<\/td><td>Ratio between the tooth counts of gear wheel and pinion<\/td><td>Defines speed reduction and torque increase<\/td><\/tr>\n<tr><td>Cone center distance<\/td><td>Relative position between pinion and wheel<\/td><td>Conditions the contact pattern, noise and durability<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<h2 class=\"article__h2\" id=\"geometry-of-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><circle cx=\"12\" cy=\"12\" r=\"10\"><\/circle><\/svg><\/span>\n Geometry of bevel pairs\n<\/h2>\n<p class=\"article__p\">Each component works on an ideal cone. The sum of the pitch angles of pinion and gear wheel defines the angle between the axes, typically 90\u00b0. The transmission ratio depends on the number of teeth: the more teeth the gear wheel has relative to the pinion, the more the speed is reduced and the available torque on the slow shaft increases.<\/p>\n<p class=\"article__p\">The cone generatrix is the ideal line connecting the cone apex to the teeth. It’s the fundamental geometric reference: the teeth develop on a conical surface, not a flat one, and the assembly must respect this geometry precisely to avoid early wear.<\/p>\n<p class=\"article__p\">Verify that <dfn id=\"def-addendum\"><span class=\"glossary-term\" data-tooltip=\"tt-addendum\" title=\"Tooth height above the pitch circle. For standard tooth geometry, it equals one module.\">addendum<\/span><\/dfn>, <dfn id=\"def-dedendum\"><span class=\"glossary-term\" data-tooltip=\"tt-dedendum\" title=\"Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.\">dedendum<\/span><\/dfn> and tooth profile are consistent with the drawing: meshing that’s too tight or too loose can only be corrected by going back to the design table, not at the assembly stage.<\/p>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">Computer-aided design and manufacturing (CAD\/CAM) allow tight tolerances and superior surface finishes, with direct effects on efficiency and durability.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"axial-backlash-in-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M8 3 3 8l5 5\"><\/path><line x1=\"3\" y1=\"8\" x2=\"21\" y2=\"8\"><\/line><path d=\"m16 21 5-5-5-5\"><\/path><line x1=\"21\" y1=\"16\" x2=\"3\" y2=\"16\"><\/line><\/svg><\/span>\n Axial backlash in bevel pairs\n<\/h2>\n<p class=\"article__p\">Axial backlash is the controlled space that lets the bevel pair work without seizing during movement, reversals and thermal expansion. Don’t confuse it with radial backlash: the axial position directly affects the contact on the tooth flanks and therefore the function of the whole transmission.<\/p>\n<p class=\"article__p\">To measure it, lock one gear and move the other back and forth without forcing, reading the displacement with a dial indicator. Repeat the measurement at several angular positions to rule out errors linked to imperfect concentricity or local deformation.<\/p>\n<p class=\"article__p\">For small modules (1-2 mm), an indicative backlash value is 0.08-0.15 mm, but the value depends on dimensions, material, speed, load, temperature and reference standard. In precision applications you tend toward the lower limit; in reducers or systems with greater expansion a wider backlash may be needed.<\/p>\n<div class=\"warnbox\">\n <div class=\"warnbox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z\"><\/path><line x1=\"12\" y1=\"9\" x2=\"12\" y2=\"13\"><\/line><line x1=\"12\" y1=\"17\" x2=\"12.01\" y2=\"17\"><\/line><\/svg>\n Warning\n <\/div>\n <p class=\"warnbox__text\">Excessive backlash generates noise, knocks on reversal and localized wear. Insufficient backlash increases friction, temperature and load on the bearings. Both cases lead to premature failure.<\/p>\n<\/div>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">The axial thrust generated by the tooth inclination requires bearings with adequate axial load capacity, especially in spiral or helical teeth.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"adjusting-the-axial-backlash\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"4\" y1=\"21\" x2=\"4\" y2=\"14\"><\/line><line x1=\"4\" y1=\"10\" x2=\"4\" y2=\"3\"><\/line><line x1=\"12\" y1=\"21\" x2=\"12\" y2=\"12\"><\/line><line x1=\"12\" y1=\"8\" x2=\"12\" y2=\"3\"><\/line><line x1=\"20\" y1=\"21\" x2=\"20\" y2=\"16\"><\/line><line x1=\"20\" y1=\"12\" x2=\"20\" y2=\"3\"><\/line><line x1=\"1\" y1=\"14\" x2=\"7\" y2=\"14\"><\/line><line x1=\"9\" y1=\"8\" x2=\"15\" y2=\"8\"><\/line><line x1=\"17\" y1=\"16\" x2=\"23\" y2=\"16\"><\/line><\/svg><\/span>\n Adjusting the axial backlash\n<\/h2>\n<p class=\"article__p\">You adjust axial backlash with calibrated shims, compensation washers or dedicated adjusters, which shift the pinion or wheel axially, changing both the contact pattern and the backlash. Minimal variations change meshing noticeably: work methodically.<\/p>\n<p class=\"article__p\">Fix the dial indicator to a rigid part. The control must be stable, repeatable and without abnormal preloads. Always record the initial values, the shims used, the final position of the gear wheel and the backlash obtained: this information is valuable for any future intervention.<\/p>\n<p class=\"article__p\">Before commissioning, rotate the pair unloaded in both directions checking noise, vibration and uniformity. If possible, also check the contact pattern with contact paste. After a brief run-in, re-measure the backlash: the first cycles settle components and surfaces, and the value can change.<\/p>\n<h2 class=\"article__h2\" id=\"5-step-guide-for-assembling-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"8\" y1=\"6\" x2=\"21\" y2=\"6\"><\/line><line x1=\"8\" y1=\"12\" x2=\"21\" y2=\"12\"><\/line><line x1=\"8\" y1=\"18\" x2=\"21\" y2=\"18\"><\/line><line x1=\"3\" y1=\"6\" x2=\"3.01\" y2=\"6\"><\/line><line x1=\"3\" y1=\"12\" x2=\"3.01\" y2=\"12\"><\/line><line x1=\"3\" y1=\"18\" x2=\"3.01\" y2=\"18\"><\/line><\/svg><\/span>\n 5-step guide for assembling bevel pairs\n<\/h2>\n<ol class=\"article__list\">\n <li><strong>Rough mounting of the first gear.<\/strong> Position the gear on the shaft roughly, without fixing it definitively, to allow subsequent adjustments.<\/li>\n <li><strong>Inserting and approaching the second gear.<\/strong> Mount the second gear at 90\u00b0 and bring the two cones together until you get a barely perceptible tooth contact, avoiding backlash.<\/li>\n <li><strong>Measuring the axial position.<\/strong> Verify the axial position of both gears relative to the structure’s reference dimensions, using precise measuring instruments.<\/li>\n <li><strong>Adjusting the axial backlash.<\/strong> Insert calibrated shims or adjustment rings to bring each gear to the nominal dimension, obtaining the axial backlash foreseen by the design.<\/li>\n <li><strong>Final check of backlash and operation.<\/strong> Manually rotate the bevel pair and measure the angular play on the locked shaft with a dial indicator, verifying that the assembly conforms to specifications.<\/li>\n<\/ol>\n<h2 class=\"article__h2\" id=\"polymer-materials-for-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10 2v7.527a2 2 0 0 1-.211.896L4.72 20.55a1 1 0 0 0 .9 1.45h12.76a1 1 0 0 0 .9-1.45l-5.069-10.127A2 2 0 0 1 14 9.527V2\"><\/path><path d=\"M8.5 2h7\"><\/path><path d=\"M7 16h10\"><\/path><\/svg><\/span>\n Polymer materials for bevel pairs\n<\/h2>\n<p class=\"article__p\">Glass-fiber PA6 (PA6+GF), POM-C and <dfn id=\"def-poliketone-pk\"><span class=\"glossary-term\" data-tooltip=\"tt-poliketone-pk\" title=\"Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.\">polyketone (PK)<\/span><\/dfn> offer light, quiet and corrosion-resistant bevel pairs. Compared with steel, they reduce weight, noise and the need for lubrication in many operating conditions. The choice depends on the specific application, not on a hierarchy of quality.<\/p>\n<p class=\"article__p\">PA6+GF offers the highest mechanical strength among the technopolymers and an excellent cost\/performance ratio. In humid environments, calculate the clearance taking into account the material’s moisture absorption: it’s a variable to manage at the design stage, not a limit that rules out PA6.<\/p>\n<p class=\"article__p\">POM-C (polyoxymethylene) is the choice when dimensional stability is the priority and loads are moderate. Low friction and high precision make it suited to smooth, quiet movements.<\/p>\n<p class=\"article__p\">PK (polyketone) is suited to chemically aggressive environments or food applications, where chemical resistance and the absence of maintenance are primary requirements.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Material<\/th><th>Strengths<\/th><th>Indicative temperature<\/th><th>Typical applications<\/th><\/tr><\/thead>\n<tbody><tr><td>Case-hardened steel<\/td><td>High strength and load capacity<\/td><td>High, depending on treatment and lubrication<\/td><td>Reducers, heavy transmissions, vehicles<\/td><\/tr>\n<tr><td>PA6+GF<\/td><td>Mechanical strength, toughness, excellent cost\/performance ratio<\/td><td>110-120 \u00b0C depending on formulation<\/td><td>Industrial machines, light transmissions<\/td><\/tr>\n<tr><td>POM-C<\/td><td>Low friction, precision, dimensional stability<\/td><td>80-90 \u00b0C<\/td><td>Quiet movements, small mechanical systems<\/td><\/tr>\n<tr><td>Polyketone (PK)<\/td><td>Chemical resistance, reduced wear, suitability for regulated sectors<\/td><td>90-100 \u00b0C<\/td><td>Packaging, food, aggressive environments<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">In steel, heat treatment (case hardening) gives surface hardness to withstand high pressures. In polymers, the choice of material and of the correct backlash performs an analogous function: load, speed, environment and maintenance guide the decision.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"common-assembly-errors-and-how-to-avoid-them\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z\"><\/path><line x1=\"12\" y1=\"9\" x2=\"12\" y2=\"13\"><\/line><line x1=\"12\" y1=\"17\" x2=\"12.01\" y2=\"17\"><\/line><\/svg><\/span>\n Common assembly errors and how to avoid them\n<\/h2>\n<p class=\"article__p\"><strong>Axis misalignment.<\/strong> Non-planar support surfaces, badly mounted bearings or tolerances not respected lead to improper contact between teeth. Before closing the structure, clean the references, use reliable instruments and check the angle between the axes.<\/p>\n<p class=\"article__p\"><strong>Wrong axial backlash.<\/strong> Too high generates noise and imprecision; too low increases friction and wear. To correct, measure at several points, use calibrated shims and verify at several angular positions.<\/p>\n<p class=\"article__p\"><strong>Improper contact between teeth.<\/strong> Indicates an error in center distance, axial position or angle. Helical-toothed bevel pairs, such as hypoids, offer smoother, more progressive contact than straight teeth, reducing noise and bearing high loads.<\/p>\n<p class=\"article__p\"><strong>Absent or insufficient lubrication.<\/strong> In metal pairs with high loads it’s essential. In technopolymers it can be reduced or absent, but scheduled maintenance is still useful to monitor wear and contaminants.<\/p>\n<h2 class=\"article__h2\" id=\"tools-and-post-assembly-quality-control\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><polyline points=\"9 11 12 14 22 4\"><\/polyline><path d=\"M21 12v7a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11\"><\/path><\/svg><\/span>\n Tools and post-assembly quality control\n<\/h2>\n<p class=\"article__p\">For professional assembly you need dial indicators, calipers, micrometers, torque wrenches, centering supports and contact pastes. In critical cases coordinate measuring machines and tooth-profile checks are used.<\/p>\n<p class=\"article__p\">After assembly, check: real backlash, contact pattern, noise, operating temperature, tightening and behavior under load. These data help future maintenance, allowing deviations to be spotted before they become failures.<\/p>\n<p class=\"article__p\">Standard bevel pairs offer fast availability and easy integration. For special materials, specific modules, non-standard ratios, noise reduction or space constraints, a custom configuration is generally the more effective choice.<\/p>\n\n <\/div>\n <\/div>\n <\/div>\n\n\n<script>\n (function () {\n var hideTimers = {};\n function positionTooltip(trigger, tooltip) {\n var margin = 8;\n tooltip.style.visibility = 'hidden';\n tooltip.style.top = '-9999px';\n tooltip.style.left = '-9999px';\n tooltip.removeAttribute('hidden');\n var ttRect = tooltip.getBoundingClientRect();\n var trRect = trigger.getBoundingClientRect();\n var vw = window.innerWidth, vh = window.innerHeight;\n var top = trRect.bottom + margin;\n var left = trRect.left;\n if (top + ttRect.height + margin > vh) {\n var above = trRect.top - ttRect.height - margin;\n top = above >= margin ? above : Math.max(margin, vh - ttRect.height - margin);\n }\n if (left + ttRect.width + margin > vw) left = vw - ttRect.width - margin;\n if (left < margin) left = margin;\n tooltip.style.top = top + 'px';\n tooltip.style.left = left + 'px';\n tooltip.style.visibility = '';\n }\n function showTooltip(ttId, trigger) {\n if (hideTimers[ttId]) { clearTimeout(hideTimers[ttId]); hideTimers[ttId] = null; }\n positionTooltip(trigger, document.getElementById(ttId));\n }\n function hideTooltip(ttId) {\n hideTimers[ttId] = setTimeout(function () {\n var tt = document.getElementById(ttId);\n if (tt) tt.setAttribute('hidden', '');\n hideTimers[ttId] = null;\n }, 180);\n }\n function cancelHide(ttId) {\n if (hideTimers[ttId]) { clearTimeout(hideTimers[ttId]); hideTimers[ttId] = null; }\n }\n document.querySelectorAll('[data-tooltip]').forEach(function (trigger) {\n var ttId = trigger.getAttribute('data-tooltip');\n trigger.addEventListener('mouseenter', function () { showTooltip(ttId, trigger); });\n trigger.addEventListener('mouseleave', function () { hideTooltip(ttId); });\n });\n ['tt-gioco-di-flanchi-backlash', 'tt-addendum', 'tt-dedendum', 'tt-poliketone-pk'].forEach(function (ttId) {\n var tt = document.getElementById(ttId);\n if (!tt) return;\n tt.addEventListener('mouseenter', function () { cancelHide(ttId); });\n tt.addEventListener('mouseleave', function () { hideTooltip(ttId); });\n });\n })();\n<\/script>\n\n<\/body><\/html>\n","protected":false},"excerpt":{"rendered":"<p>Axis and axial backlash adjustment to prevent load concentration on the tooth, localized wear, and premature failure.<\/p>\n","protected":false},"parent":0,"template":"","meta":{"_acf_changed":false},"campo-applicazione":[5457],"categoria-ct":[5445],"class_list":["post-25597","centro-tecnico","type-centro-tecnico","status-publish","hentry","campo-applicazione-assembly","categoria-ct-s-torque-and-s-speed-bevel-gear-sets"],"acf":[],"yoast_head":"\n<title>Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop<\/title>\n<meta name=\"description\" content=\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop\" \/>\n<meta property=\"og:description\" content=\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/\" \/>\n<meta property=\"og:site_name\" content=\"Stagnoli Gears Shop\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/StagnoliGears\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-10T11:57:27+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\",\"name\":\"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#website\"},\"datePublished\":\"2026-06-30T09:09:24+00:00\",\"dateModified\":\"2026-07-10T11:57:27+00:00\",\"description\":\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Bevel gear assembly: complete guide to geometry and axial backlash\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#website\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\",\"name\":\"Stagnoli\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#organization\",\"name\":\"Stagnoli Gears\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/wp-content\\\/uploads\\\/logo-stagnoli-shop.svg\",\"contentUrl\":\"https:\\\/\\\/shop.stagnoligears.com\\\/wp-content\\\/uploads\\\/logo-stagnoli-shop.svg\",\"width\":1,\"height\":1,\"caption\":\"Stagnoli Gears\"},\"image\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/StagnoliGears\",\"https:\\\/\\\/www.youtube.com\\\/@stagnoli_gears\",\"https:\\\/\\\/www.linkedin.com\\\/showcase\\\/stagnoli-gears\\\/\"]}]}<\/script>\n","yoast_head_json":{"title":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","og_locale":"en_US","og_type":"article","og_title":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","og_description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","og_url":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","og_site_name":"Stagnoli Gears Shop","article_publisher":"https:\/\/www.facebook.com\/StagnoliGears","article_modified_time":"2026-07-10T11:57:27+00:00","twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","url":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","name":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","isPartOf":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#website"},"datePublished":"2026-06-30T09:09:24+00:00","dateModified":"2026-07-10T11:57:27+00:00","description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","breadcrumb":{"@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/shop.stagnoligears.com\/en\/"},{"@type":"ListItem","position":2,"name":"Bevel gear assembly: complete guide to geometry and axial backlash"}]},{"@type":"WebSite","@id":"https:\/\/shop.stagnoligears.com\/en\/#website","url":"https:\/\/shop.stagnoligears.com\/en\/","name":"Stagnoli","description":"","publisher":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/shop.stagnoligears.com\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/shop.stagnoligears.com\/en\/#organization","name":"Stagnoli Gears","url":"https:\/\/shop.stagnoligears.com\/en\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/shop.stagnoligears.com\/en\/#\/schema\/logo\/image\/","url":"https:\/\/shop.stagnoligears.com\/wp-content\/uploads\/logo-stagnoli-shop.svg","contentUrl":"https:\/\/shop.stagnoligears.com\/wp-content\/uploads\/logo-stagnoli-shop.svg","width":1,"height":1,"caption":"Stagnoli Gears"},"image":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/StagnoliGears","https:\/\/www.youtube.com\/@stagnoli_gears","https:\/\/www.linkedin.com\/showcase\/stagnoli-gears\/"]}]}},"_links":{"self":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/centro-tecnico\/25597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/centro-tecnico"}],"about":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/types\/centro-tecnico"}],"wp:attachment":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/media?parent=25597"}],"wp:term":[{"taxonomy":"campo-applicazione","embeddable":true,"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/campo-applicazione?post=25597"},{"taxonomy":"categoria-ct","embeddable":true,"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/categoria-ct?post=25597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

{"id":25597,"date":"2026-06-30T11:09:24","date_gmt":"2026-06-30T09:09:24","guid":{"rendered":"https:\/\/shop.stagnoligears.com\/?post_type=centro-tecnico&p=25597"},"modified":"2026-07-10T13:57:27","modified_gmt":"2026-07-10T11:57:27","slug":"bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash","status":"publish","type":"centro-tecnico","link":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","title":{"rendered":"Bevel gear assembly: complete guide to geometry and axial backlash"},"content":{"rendered":"\n\n \n \n \n Bevel gear assembly: complete guide to geometry and axial backlash<\/title>\n\n <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin=\"\">\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&display=swap\" rel=\"stylesheet\">\n\n <style>\n *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }\n\n :root {\n --green: #1a6b3c;\n --green-dark: #0f4a28;\n --green-mid: #2d8a55;\n --green-light: #e8f4ed;\n --green-xlight: #f2faf5;\n --amber: #b45309;\n --amber-light: #fef3c7;\n\n --bg: #ffffff;\n --bg-soft: #f8f9fa;\n --bg-muted: #f1f3f5;\n --border: #e5e7eb;\n --border-mid: #d1d5db;\n\n --text-primary: #111827;\n --text-secondary: #4b5563;\n --text-muted: #9ca3af;\n\n --radius-sm: 6px;\n --radius-md: 8px;\n --radius-lg: 12px;\n --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);\n --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);\n }\n\n body { min-height: 100vh; }\n\n .article-page {\n display: flex;\n flex-direction: column;\n min-height: 100vh;\n }\n\n .article-body {\n padding: 40px 28px 64px;\n display: flex;\n align-items: flex-start;\n gap: 36px;\n max-width: 1180px;\n margin: 0 auto;\n width: 100%;\n font-family: 'Inter', sans-serif;\n font-size: 15px;\n letter-spacing: 0.02em;\n color: var(--text-primary);\n }\n\n .article-body__main {\n flex: 1;\n min-width: 0;\n max-width: 820px;\n }\n\n .article__title {\n font-size: 24px;\n font-weight: 700;\n color: var(--text-primary);\n line-height: 1.3;\n margin-bottom: 8px;\n }\n\n .article__subtitle {\n font-size: 15px;\n color: var(--text-secondary);\n line-height: 1.75;\n margin-bottom: 24px;\n }\n\n .article__h2 {\n display: flex;\n align-items: center;\n gap: 9px;\n font-size: 17px;\n font-weight: 600;\n color: var(--text-primary);\n padding-bottom: 10px;\n border-bottom: 1px solid var(--border);\n margin-top: 28px;\n margin-bottom: 14px;\n }\n\n .article__h2-icon {\n display: flex;\n align-items: center;\n color: var(--green);\n }\n\n .article__p {\n font-size: 15px;\n color: var(--text-secondary);\n line-height: 1.8;\n margin-bottom: 14px;\n }\n\n .article__list {\n margin: 0 0 14px 0;\n padding-left: 20px;\n list-style: disc;\n }\n\n .article__list li {\n font-size: 14.5px;\n color: var(--text-secondary);\n line-height: 1.8;\n margin-bottom: 4px;\n }\n\n \/* ============================================================\n CALLOUT BOXES\n ============================================================ *\/\n .infobox {\n background: var(--green-xlight);\n border-left: 3px solid var(--green);\n border-radius: 0 var(--radius-md) var(--radius-md) 0;\n padding: 12px 16px;\n margin: 16px 0;\n }\n\n .infobox__title {\n display: flex;\n align-items: center;\n gap: 6px;\n font-size: 13px;\n font-weight: 600;\n color: var(--green-dark);\n margin-bottom: 5px;\n }\n\n .infobox__text {\n font-size: 13.5px;\n color: var(--green);\n line-height: 1.65;\n }\n\n .infobox--grey {\n background: var(--bg-muted);\n border-left-color: var(--border-mid);\n }\n\n .infobox--grey .infobox__title { color: var(--text-secondary); }\n .infobox--grey .infobox__text { color: var(--text-secondary); }\n\n .warnbox {\n background: var(--amber-light);\n border-left: 3px solid var(--amber);\n border-radius: 0 var(--radius-md) var(--radius-md) 0;\n padding: 12px 16px;\n margin: 16px 0;\n }\n\n .warnbox__title {\n display: flex;\n align-items: center;\n gap: 6px;\n font-size: 13px;\n font-weight: 600;\n color: #92400e;\n margin-bottom: 5px;\n }\n\n .warnbox__text {\n font-size: 13.5px;\n color: var(--amber);\n line-height: 1.65;\n }\n\n \/* ============================================================\n IMAGE\n ============================================================ *\/\n .article__figure {\n margin: 20px 0;\n text-align: center;\n }\n\n .article__figure img {\n max-width: 100%;\n }\n\n .article__figure figcaption {\n font-size: 13px;\n color: var(--text-muted);\n margin-top: 8px;\n }\n\n \/* ============================================================\n TABLE\n ============================================================ *\/\n .article__table-wrap {\n overflow-x: auto;\n margin: 16px 0;\n border-radius: var(--radius-md);\n border: 1px solid var(--border);\n }\n\n .article__table {\n width: 100%;\n border-collapse: collapse;\n font-size: 14px;\n }\n\n .article__table thead {\n background: var(--green);\n }\n\n .article__table th {\n text-align: left;\n font-weight: 600;\n color: #ffffff;\n padding: 10px 14px;\n border-bottom: 1px solid var(--border);\n white-space: nowrap;\n }\n\n .article__table td {\n padding: 10px 14px;\n color: var(--text-secondary);\n border-bottom: 1px solid var(--border);\n line-height: 1.6;\n vertical-align: top;\n }\n\n .article__table tr:last-child td { border-bottom: none; }\n\n .badge {\n display: inline-block;\n font-size: 12px;\n font-weight: 600;\n padding: 2px 8px;\n border-radius: 20px;\n background: var(--green-light);\n color: var(--green-dark);\n }\n\n \/* ============================================================\n RESPONSIVE\n ============================================================ *\/\n @media (max-width: 900px) {\n .article-body { flex-direction: column; padding: 20px 20px 48px; }\n }\n \n \/* Glossary tooltips *\/\n .glossary-term {\n border-bottom: 1px dotted var(--green);\n color: var(--green);\n font-style: italic;\n cursor: help;\n }\n .glossary-tooltip {\n position: fixed;\n z-index: 9999;\n background: #fff;\n border: 1px solid var(--border-mid);\n border-radius: var(--radius-md);\n box-shadow: var(--shadow-md);\n padding: 10px 14px;\n max-width: 300px;\n font-family: 'Inter', sans-serif;\n font-size: 13px;\n }\n .glossary-tooltip__title {\n font-weight: 600;\n color: var(--text-primary);\n margin-bottom: 4px;\n }\n .glossary-tooltip__def {\n font-size: 12.5px;\n color: var(--text-secondary);\n line-height: 1.6;\n }\n .glossary-tooltip__tag {\n display: inline-block;\n margin-top: 6px;\n font-size: 9px;\n font-weight: 600;\n padding: 2px 7px;\n border-radius: 20px;\n background: var(--green-light);\n color: var(--green-dark);\n text-transform: uppercase;\n letter-spacing: 0.04em;\n }\n\n <\/style>\n<\/head>\n<body>\n\n<div id=\"tt-gioco-di-flanchi-backlash\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Backlash<\/div>\n <div class=\"glossary-tooltip__def\">Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-addendum\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Addendum<\/div>\n <div class=\"glossary-tooltip__def\">Tooth height above the pitch circle. For standard tooth geometry, it equals one module.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-dedendum\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Dedendum<\/div>\n <div class=\"glossary-tooltip__def\">Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-poliketone-pk\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Polyketone (PK)<\/div>\n <div class=\"glossary-tooltip__def\">Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n\n <div class=\"article-page\">\n <div class=\"article-body\">\n <div class=\"article-body__main\"><script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@graph\": [\n {\n \"@type\": \"TechArticle\",\n \"@id\": \"#article\",\n \"headline\": \"Bevel gear assembly: complete guide to geometry and axial backlash\",\n \"description\": \"A badly assembled bevel pair doesn't give immediate signals. It works, at first. Then the noise arrives, then wear concentrated on a narrow zone of the tooth, then the failure. In almost all cases, the root is a single one: geometry out of tolerance, misaligned axes or wrong axial backlash.\",\n \"inLanguage\": \"en\",\n \"mentions\": [\n {\n \"@id\": \"#term-gioco-di-flanchi-backlash\"\n },\n {\n \"@id\": \"#term-addendum\"\n },\n {\n \"@id\": \"#term-dedendum\"\n },\n {\n \"@id\": \"#term-poliketone-pk\"\n }\n ]\n },\n {\n \"@type\": \"DefinedTermSet\",\n \"@id\": \"#glossario\",\n \"name\": \"Glossario - Bevel gear assembly: complete guide to geometry and axial backlash\",\n \"hasDefinedTerm\": [\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-gioco-di-flanchi-backlash\",\n \"name\": \"Backlash\",\n \"description\": \"Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-addendum\",\n \"name\": \"Addendum\",\n \"description\": \"Tooth height above the pitch circle. For standard tooth geometry, it equals one module.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-dedendum\",\n \"name\": \"Dedendum\",\n \"description\": \"Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.\",\n \"inDefinedTermSet\": \"#glossario\"\n },\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-poliketone-pk\",\n \"name\": \"Polyketone (PK)\",\n \"description\": \"Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.\",\n \"inDefinedTermSet\": \"#glossario\"\n }\n ]\n }\n ]\n}\n<\/script>\n\n\n\n <h1 class=\"article__title\">Bevel gear assembly: complete guide to geometry and axial backlash<\/h1>\n<p class=\"article__subtitle\">A badly assembled bevel pair doesn’t give immediate signals. It works, at first. Then the noise arrives, then wear concentrated on a narrow zone of the tooth, then the failure. In almost all cases, the root is a single one: geometry out of tolerance, misaligned axes or wrong axial <dfn id=\"def-gioco-di-flanchi-backlash\"><span class=\"glossary-term\" data-tooltip=\"tt-gioco-di-flanchi-backlash\" title=\"Free clearance between the flanks of two mating teeth, measured at the pitch circle. It prevents jamming due to thermal expansion or assembly errors.\">backlash<\/span><\/dfn>.<\/p>\n<h2 class=\"article__h2\" id=\"fundamental-geometric-characteristics\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"m3 20 9-16 9 16H3z\"><\/path><\/svg><\/span>\n Fundamental geometric characteristics\n<\/h2>\n<p class=\"article__p\">Bevel pairs are pairs of gears that change the direction of motion transmission by working at 90\u00b0. Unlike spur gears, the teeth aren’t parallel to the axis: they follow a truncated-cone shape, which allows motion and power to be transferred between intersecting axes.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Parameter<\/th><th>Meaning<\/th><th>Importance in assembly<\/th><\/tr><\/thead>\n<tbody><tr><td>Pitch angle<\/td><td>Angle of the pitch cone relative to the gear axis<\/td><td>Determines the shaft-crossing angle and the correct contact position<\/td><\/tr>\n<tr><td>Module<\/td><td>Base dimension of the tooth and the teeth<\/td><td>Affects strength, dimensions, backlash and load capacity<\/td><\/tr>\n<tr><td>Transmission ratio<\/td><td>Ratio between the tooth counts of gear wheel and pinion<\/td><td>Defines speed reduction and torque increase<\/td><\/tr>\n<tr><td>Cone center distance<\/td><td>Relative position between pinion and wheel<\/td><td>Conditions the contact pattern, noise and durability<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<h2 class=\"article__h2\" id=\"geometry-of-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><circle cx=\"12\" cy=\"12\" r=\"10\"><\/circle><\/svg><\/span>\n Geometry of bevel pairs\n<\/h2>\n<p class=\"article__p\">Each component works on an ideal cone. The sum of the pitch angles of pinion and gear wheel defines the angle between the axes, typically 90\u00b0. The transmission ratio depends on the number of teeth: the more teeth the gear wheel has relative to the pinion, the more the speed is reduced and the available torque on the slow shaft increases.<\/p>\n<p class=\"article__p\">The cone generatrix is the ideal line connecting the cone apex to the teeth. It’s the fundamental geometric reference: the teeth develop on a conical surface, not a flat one, and the assembly must respect this geometry precisely to avoid early wear.<\/p>\n<p class=\"article__p\">Verify that <dfn id=\"def-addendum\"><span class=\"glossary-term\" data-tooltip=\"tt-addendum\" title=\"Tooth height above the pitch circle. For standard tooth geometry, it equals one module.\">addendum<\/span><\/dfn>, <dfn id=\"def-dedendum\"><span class=\"glossary-term\" data-tooltip=\"tt-dedendum\" title=\"Tooth height below the pitch circle, down to the root circle. For standard tooth geometry, it equals 1.25 modules.\">dedendum<\/span><\/dfn> and tooth profile are consistent with the drawing: meshing that’s too tight or too loose can only be corrected by going back to the design table, not at the assembly stage.<\/p>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">Computer-aided design and manufacturing (CAD\/CAM) allow tight tolerances and superior surface finishes, with direct effects on efficiency and durability.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"axial-backlash-in-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M8 3 3 8l5 5\"><\/path><line x1=\"3\" y1=\"8\" x2=\"21\" y2=\"8\"><\/line><path d=\"m16 21 5-5-5-5\"><\/path><line x1=\"21\" y1=\"16\" x2=\"3\" y2=\"16\"><\/line><\/svg><\/span>\n Axial backlash in bevel pairs\n<\/h2>\n<p class=\"article__p\">Axial backlash is the controlled space that lets the bevel pair work without seizing during movement, reversals and thermal expansion. Don’t confuse it with radial backlash: the axial position directly affects the contact on the tooth flanks and therefore the function of the whole transmission.<\/p>\n<p class=\"article__p\">To measure it, lock one gear and move the other back and forth without forcing, reading the displacement with a dial indicator. Repeat the measurement at several angular positions to rule out errors linked to imperfect concentricity or local deformation.<\/p>\n<p class=\"article__p\">For small modules (1-2 mm), an indicative backlash value is 0.08-0.15 mm, but the value depends on dimensions, material, speed, load, temperature and reference standard. In precision applications you tend toward the lower limit; in reducers or systems with greater expansion a wider backlash may be needed.<\/p>\n<div class=\"warnbox\">\n <div class=\"warnbox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z\"><\/path><line x1=\"12\" y1=\"9\" x2=\"12\" y2=\"13\"><\/line><line x1=\"12\" y1=\"17\" x2=\"12.01\" y2=\"17\"><\/line><\/svg>\n Warning\n <\/div>\n <p class=\"warnbox__text\">Excessive backlash generates noise, knocks on reversal and localized wear. Insufficient backlash increases friction, temperature and load on the bearings. Both cases lead to premature failure.<\/p>\n<\/div>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">The axial thrust generated by the tooth inclination requires bearings with adequate axial load capacity, especially in spiral or helical teeth.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"adjusting-the-axial-backlash\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"4\" y1=\"21\" x2=\"4\" y2=\"14\"><\/line><line x1=\"4\" y1=\"10\" x2=\"4\" y2=\"3\"><\/line><line x1=\"12\" y1=\"21\" x2=\"12\" y2=\"12\"><\/line><line x1=\"12\" y1=\"8\" x2=\"12\" y2=\"3\"><\/line><line x1=\"20\" y1=\"21\" x2=\"20\" y2=\"16\"><\/line><line x1=\"20\" y1=\"12\" x2=\"20\" y2=\"3\"><\/line><line x1=\"1\" y1=\"14\" x2=\"7\" y2=\"14\"><\/line><line x1=\"9\" y1=\"8\" x2=\"15\" y2=\"8\"><\/line><line x1=\"17\" y1=\"16\" x2=\"23\" y2=\"16\"><\/line><\/svg><\/span>\n Adjusting the axial backlash\n<\/h2>\n<p class=\"article__p\">You adjust axial backlash with calibrated shims, compensation washers or dedicated adjusters, which shift the pinion or wheel axially, changing both the contact pattern and the backlash. Minimal variations change meshing noticeably: work methodically.<\/p>\n<p class=\"article__p\">Fix the dial indicator to a rigid part. The control must be stable, repeatable and without abnormal preloads. Always record the initial values, the shims used, the final position of the gear wheel and the backlash obtained: this information is valuable for any future intervention.<\/p>\n<p class=\"article__p\">Before commissioning, rotate the pair unloaded in both directions checking noise, vibration and uniformity. If possible, also check the contact pattern with contact paste. After a brief run-in, re-measure the backlash: the first cycles settle components and surfaces, and the value can change.<\/p>\n<h2 class=\"article__h2\" id=\"5-step-guide-for-assembling-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"8\" y1=\"6\" x2=\"21\" y2=\"6\"><\/line><line x1=\"8\" y1=\"12\" x2=\"21\" y2=\"12\"><\/line><line x1=\"8\" y1=\"18\" x2=\"21\" y2=\"18\"><\/line><line x1=\"3\" y1=\"6\" x2=\"3.01\" y2=\"6\"><\/line><line x1=\"3\" y1=\"12\" x2=\"3.01\" y2=\"12\"><\/line><line x1=\"3\" y1=\"18\" x2=\"3.01\" y2=\"18\"><\/line><\/svg><\/span>\n 5-step guide for assembling bevel pairs\n<\/h2>\n<ol class=\"article__list\">\n <li><strong>Rough mounting of the first gear.<\/strong> Position the gear on the shaft roughly, without fixing it definitively, to allow subsequent adjustments.<\/li>\n <li><strong>Inserting and approaching the second gear.<\/strong> Mount the second gear at 90\u00b0 and bring the two cones together until you get a barely perceptible tooth contact, avoiding backlash.<\/li>\n <li><strong>Measuring the axial position.<\/strong> Verify the axial position of both gears relative to the structure’s reference dimensions, using precise measuring instruments.<\/li>\n <li><strong>Adjusting the axial backlash.<\/strong> Insert calibrated shims or adjustment rings to bring each gear to the nominal dimension, obtaining the axial backlash foreseen by the design.<\/li>\n <li><strong>Final check of backlash and operation.<\/strong> Manually rotate the bevel pair and measure the angular play on the locked shaft with a dial indicator, verifying that the assembly conforms to specifications.<\/li>\n<\/ol>\n<h2 class=\"article__h2\" id=\"polymer-materials-for-bevel-pairs\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10 2v7.527a2 2 0 0 1-.211.896L4.72 20.55a1 1 0 0 0 .9 1.45h12.76a1 1 0 0 0 .9-1.45l-5.069-10.127A2 2 0 0 1 14 9.527V2\"><\/path><path d=\"M8.5 2h7\"><\/path><path d=\"M7 16h10\"><\/path><\/svg><\/span>\n Polymer materials for bevel pairs\n<\/h2>\n<p class=\"article__p\">Glass-fiber PA6 (PA6+GF), POM-C and <dfn id=\"def-poliketone-pk\"><span class=\"glossary-term\" data-tooltip=\"tt-poliketone-pk\" title=\"Semi-crystalline technopolymer with a very low friction coefficient and high chemical resistance. An alternative to POM in environments involving aggressive lubricants or fuels.\">polyketone (PK)<\/span><\/dfn> offer light, quiet and corrosion-resistant bevel pairs. Compared with steel, they reduce weight, noise and the need for lubrication in many operating conditions. The choice depends on the specific application, not on a hierarchy of quality.<\/p>\n<p class=\"article__p\">PA6+GF offers the highest mechanical strength among the technopolymers and an excellent cost\/performance ratio. In humid environments, calculate the clearance taking into account the material’s moisture absorption: it’s a variable to manage at the design stage, not a limit that rules out PA6.<\/p>\n<p class=\"article__p\">POM-C (polyoxymethylene) is the choice when dimensional stability is the priority and loads are moderate. Low friction and high precision make it suited to smooth, quiet movements.<\/p>\n<p class=\"article__p\">PK (polyketone) is suited to chemically aggressive environments or food applications, where chemical resistance and the absence of maintenance are primary requirements.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Material<\/th><th>Strengths<\/th><th>Indicative temperature<\/th><th>Typical applications<\/th><\/tr><\/thead>\n<tbody><tr><td>Case-hardened steel<\/td><td>High strength and load capacity<\/td><td>High, depending on treatment and lubrication<\/td><td>Reducers, heavy transmissions, vehicles<\/td><\/tr>\n<tr><td>PA6+GF<\/td><td>Mechanical strength, toughness, excellent cost\/performance ratio<\/td><td>110-120 \u00b0C depending on formulation<\/td><td>Industrial machines, light transmissions<\/td><\/tr>\n<tr><td>POM-C<\/td><td>Low friction, precision, dimensional stability<\/td><td>80-90 \u00b0C<\/td><td>Quiet movements, small mechanical systems<\/td><\/tr>\n<tr><td>Polyketone (PK)<\/td><td>Chemical resistance, reduced wear, suitability for regulated sectors<\/td><td>90-100 \u00b0C<\/td><td>Packaging, food, aggressive environments<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<div class=\"infobox infobox--grey\">\n <div class=\"infobox__title\">\n <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M14.7 6.3a1 1 0 0 0 0 1.4l1.6 1.6a1 1 0 0 0 1.4 0l3.77-3.77a6 6 0 0 1-7.94 7.94l-6.91 6.91a2.12 2.12 0 0 1-3-3l6.91-6.91a6 6 0 0 1 7.94-7.94l-3.76 3.76z\"><\/path><\/svg>\n Technical note\n <\/div>\n <p class=\"infobox__text\">In steel, heat treatment (case hardening) gives surface hardness to withstand high pressures. In polymers, the choice of material and of the correct backlash performs an analogous function: load, speed, environment and maintenance guide the decision.<\/p>\n<\/div>\n<h2 class=\"article__h2\" id=\"common-assembly-errors-and-how-to-avoid-them\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z\"><\/path><line x1=\"12\" y1=\"9\" x2=\"12\" y2=\"13\"><\/line><line x1=\"12\" y1=\"17\" x2=\"12.01\" y2=\"17\"><\/line><\/svg><\/span>\n Common assembly errors and how to avoid them\n<\/h2>\n<p class=\"article__p\"><strong>Axis misalignment.<\/strong> Non-planar support surfaces, badly mounted bearings or tolerances not respected lead to improper contact between teeth. Before closing the structure, clean the references, use reliable instruments and check the angle between the axes.<\/p>\n<p class=\"article__p\"><strong>Wrong axial backlash.<\/strong> Too high generates noise and imprecision; too low increases friction and wear. To correct, measure at several points, use calibrated shims and verify at several angular positions.<\/p>\n<p class=\"article__p\"><strong>Improper contact between teeth.<\/strong> Indicates an error in center distance, axial position or angle. Helical-toothed bevel pairs, such as hypoids, offer smoother, more progressive contact than straight teeth, reducing noise and bearing high loads.<\/p>\n<p class=\"article__p\"><strong>Absent or insufficient lubrication.<\/strong> In metal pairs with high loads it’s essential. In technopolymers it can be reduced or absent, but scheduled maintenance is still useful to monitor wear and contaminants.<\/p>\n<h2 class=\"article__h2\" id=\"tools-and-post-assembly-quality-control\">\n <span class=\"article__h2-icon\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><polyline points=\"9 11 12 14 22 4\"><\/polyline><path d=\"M21 12v7a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11\"><\/path><\/svg><\/span>\n Tools and post-assembly quality control\n<\/h2>\n<p class=\"article__p\">For professional assembly you need dial indicators, calipers, micrometers, torque wrenches, centering supports and contact pastes. In critical cases coordinate measuring machines and tooth-profile checks are used.<\/p>\n<p class=\"article__p\">After assembly, check: real backlash, contact pattern, noise, operating temperature, tightening and behavior under load. These data help future maintenance, allowing deviations to be spotted before they become failures.<\/p>\n<p class=\"article__p\">Standard bevel pairs offer fast availability and easy integration. For special materials, specific modules, non-standard ratios, noise reduction or space constraints, a custom configuration is generally the more effective choice.<\/p>\n\n <\/div>\n <\/div>\n <\/div>\n\n\n<script>\n (function () {\n var hideTimers = {};\n function positionTooltip(trigger, tooltip) {\n var margin = 8;\n tooltip.style.visibility = 'hidden';\n tooltip.style.top = '-9999px';\n tooltip.style.left = '-9999px';\n tooltip.removeAttribute('hidden');\n var ttRect = tooltip.getBoundingClientRect();\n var trRect = trigger.getBoundingClientRect();\n var vw = window.innerWidth, vh = window.innerHeight;\n var top = trRect.bottom + margin;\n var left = trRect.left;\n if (top + ttRect.height + margin > vh) {\n var above = trRect.top - ttRect.height - margin;\n top = above >= margin ? above : Math.max(margin, vh - ttRect.height - margin);\n }\n if (left + ttRect.width + margin > vw) left = vw - ttRect.width - margin;\n if (left < margin) left = margin;\n tooltip.style.top = top + 'px';\n tooltip.style.left = left + 'px';\n tooltip.style.visibility = '';\n }\n function showTooltip(ttId, trigger) {\n if (hideTimers[ttId]) { clearTimeout(hideTimers[ttId]); hideTimers[ttId] = null; }\n positionTooltip(trigger, document.getElementById(ttId));\n }\n function hideTooltip(ttId) {\n hideTimers[ttId] = setTimeout(function () {\n var tt = document.getElementById(ttId);\n if (tt) tt.setAttribute('hidden', '');\n hideTimers[ttId] = null;\n }, 180);\n }\n function cancelHide(ttId) {\n if (hideTimers[ttId]) { clearTimeout(hideTimers[ttId]); hideTimers[ttId] = null; }\n }\n document.querySelectorAll('[data-tooltip]').forEach(function (trigger) {\n var ttId = trigger.getAttribute('data-tooltip');\n trigger.addEventListener('mouseenter', function () { showTooltip(ttId, trigger); });\n trigger.addEventListener('mouseleave', function () { hideTooltip(ttId); });\n });\n ['tt-gioco-di-flanchi-backlash', 'tt-addendum', 'tt-dedendum', 'tt-poliketone-pk'].forEach(function (ttId) {\n var tt = document.getElementById(ttId);\n if (!tt) return;\n tt.addEventListener('mouseenter', function () { cancelHide(ttId); });\n tt.addEventListener('mouseleave', function () { hideTooltip(ttId); });\n });\n })();\n<\/script>\n\n<\/body><\/html>\n","protected":false},"excerpt":{"rendered":"<p>Axis and axial backlash adjustment to prevent load concentration on the tooth, localized wear, and premature failure.<\/p>\n","protected":false},"parent":0,"template":"","meta":{"_acf_changed":false},"campo-applicazione":[5457],"categoria-ct":[5445],"class_list":["post-25597","centro-tecnico","type-centro-tecnico","status-publish","hentry","campo-applicazione-assembly","categoria-ct-s-torque-and-s-speed-bevel-gear-sets"],"acf":[],"yoast_head":"\n<title>Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop<\/title>\n<meta name=\"description\" content=\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop\" \/>\n<meta property=\"og:description\" content=\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/\" \/>\n<meta property=\"og:site_name\" content=\"Stagnoli Gears Shop\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/StagnoliGears\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-10T11:57:27+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\",\"name\":\"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#website\"},\"datePublished\":\"2026-06-30T09:09:24+00:00\",\"dateModified\":\"2026-07-10T11:57:27+00:00\",\"description\":\"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/technical-hub\\\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Bevel gear assembly: complete guide to geometry and axial backlash\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#website\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\",\"name\":\"Stagnoli\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#organization\",\"name\":\"Stagnoli Gears\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/shop.stagnoligears.com\\\/wp-content\\\/uploads\\\/logo-stagnoli-shop.svg\",\"contentUrl\":\"https:\\\/\\\/shop.stagnoligears.com\\\/wp-content\\\/uploads\\\/logo-stagnoli-shop.svg\",\"width\":1,\"height\":1,\"caption\":\"Stagnoli Gears\"},\"image\":{\"@id\":\"https:\\\/\\\/shop.stagnoligears.com\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/StagnoliGears\",\"https:\\\/\\\/www.youtube.com\\\/@stagnoli_gears\",\"https:\\\/\\\/www.linkedin.com\\\/showcase\\\/stagnoli-gears\\\/\"]}]}<\/script>\n","yoast_head_json":{"title":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","og_locale":"en_US","og_type":"article","og_title":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","og_description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","og_url":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","og_site_name":"Stagnoli Gears Shop","article_publisher":"https:\/\/www.facebook.com\/StagnoliGears","article_modified_time":"2026-07-10T11:57:27+00:00","twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","url":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/","name":"Bevel Gear Assembly and Axial Backlash | Stagnoli Gears Shop","isPartOf":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#website"},"datePublished":"2026-06-30T09:09:24+00:00","dateModified":"2026-07-10T11:57:27+00:00","description":"Complete guide to bevel gear assembly: geometry, pitch angles, cone positioning, shaft alignment and axial backlash for reliable gear operation.","breadcrumb":{"@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/bevel-gear-assembly-complete-guide-to-geometry-and-axial-backlash\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/shop.stagnoligears.com\/en\/"},{"@type":"ListItem","position":2,"name":"Bevel gear assembly: complete guide to geometry and axial backlash"}]},{"@type":"WebSite","@id":"https:\/\/shop.stagnoligears.com\/en\/#website","url":"https:\/\/shop.stagnoligears.com\/en\/","name":"Stagnoli","description":"","publisher":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/shop.stagnoligears.com\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/shop.stagnoligears.com\/en\/#organization","name":"Stagnoli Gears","url":"https:\/\/shop.stagnoligears.com\/en\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/shop.stagnoligears.com\/en\/#\/schema\/logo\/image\/","url":"https:\/\/shop.stagnoligears.com\/wp-content\/uploads\/logo-stagnoli-shop.svg","contentUrl":"https:\/\/shop.stagnoligears.com\/wp-content\/uploads\/logo-stagnoli-shop.svg","width":1,"height":1,"caption":"Stagnoli Gears"},"image":{"@id":"https:\/\/shop.stagnoligears.com\/en\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/StagnoliGears","https:\/\/www.youtube.com\/@stagnoli_gears","https:\/\/www.linkedin.com\/showcase\/stagnoli-gears\/"]}]}},"_links":{"self":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/centro-tecnico\/25597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/centro-tecnico"}],"about":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/types\/centro-tecnico"}],"wp:attachment":[{"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/media?parent=25597"}],"wp:term":[{"taxonomy":"campo-applicazione","embeddable":true,"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/campo-applicazione?post=25597"},{"taxonomy":"categoria-ct","embeddable":true,"href":"https:\/\/shop.stagnoligears.com\/en\/wp-json\/wp\/v2\/categoria-ct?post=25597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}