Friction, moisture and wear: choosing the right technopolymer for gears<\/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; 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}\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-igroscopicita\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Hygroscopicity<\/div>\n <div class=\"glossary-tooltip__def\">Property of a material to absorb moisture from the surrounding environment. In technopolymers such as PA6 and PA66, it causes dimensional swelling that may reduce backlash to zero.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-stick-slip\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Stick-slip<\/div>\n <div class=\"glossary-tooltip__def\">Irregular motion phenomenon characterised by alternating static adhesion and abrupt sliding between two surfaces. It generates vibrations, noise and accelerated wear.<\/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\": \"Friction, moisture and wear: choosing the right technopolymer for gears\",\n \"description\": \"When designing technopolymer gears, the choice between glass-fiber reinforced PA6, POM-C and PK (polyketone) is never interchangeable. Each material answers to different tribological and environmental logics. A selection error translates into early wear, loss of kinematic precision or, in the worst cases, brittle tooth fracture.\",\n \"inLanguage\": \"en\",\n \"mentions\": [\n {\n \"@id\": \"#term-igroscopicita\"\n },\n {\n \"@id\": \"#term-stick-slip\"\n },\n {\n \"@id\": \"#term-poliketone-pk\"\n }\n ]\n },\n {\n \"@type\": \"DefinedTermSet\",\n \"@id\": \"#glossario\",\n \"name\": \"Glossario - Friction, moisture and wear: choosing the right technopolymer for gears\",\n \"hasDefinedTerm\": [\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-igroscopicita\",\n \"name\": \"Hygroscopicity\",\n \"description\": \"Property of a material to absorb moisture from the surrounding environment. 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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\">Friction, moisture and wear: choosing the right technopolymer for gears<\/h1>\n<p class=\"article__subtitle\">When designing technopolymer gears, the choice between glass-fiber reinforced PA6, POM-C and PK (polyketone) is never interchangeable. Each material answers to different tribological and environmental logics. A selection error translates into early wear, loss of kinematic precision or, in the worst cases, brittle tooth fracture.<\/p>\n<p class=\"article__p\">The critical problem is almost never tensile strength, often abundant relative to nominal loads. It’s the combination of friction coefficient, <dfn id=\"def-igroscopicita\"><span class=\"glossary-term\" data-tooltip=\"tt-igroscopicita\" title=\"Property of a material to absorb moisture from the surrounding environment. In technopolymers such as PA6 and PA66, it causes dimensional swelling that may reduce backlash to zero.\">hygroscopicity<\/span><\/dfn> and dimensional stability under cyclic load. A PA6 gear that absorbs moisture in a humid environment can change its meshing clearance enough to cause interference. A POM-C one subjected to impulsive shocks can fail by brittleness. A PK one might be more balanced, but at a cost that the application has to justify.<\/p>\n<h2 class=\"article__h2\" id=\"glass-fiber-pa6-pom-c-and-pk-where-they-truly-diverge\">\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=\"18\" y1=\"20\" x2=\"18\" y2=\"10\"><\/line><line x1=\"12\" y1=\"20\" x2=\"12\" y2=\"4\"><\/line><line x1=\"6\" y1=\"20\" x2=\"6\" y2=\"14\"><\/line><\/svg><\/span>\n Glass-fiber PA6, POM-C and PK: where they truly diverge\n<\/h2>\n<p class=\"article__p\">These three materials don’t differ by grade of quality: each governs a precise application territory, with minimal overlap.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Property<\/th><th>PA6 + glass fiber<\/th><th>POM-C<\/th><th>PK (polyketone)<\/th><\/tr><\/thead>\n<tbody><tr><td>Mechanical strength (static load)<\/td><td>\u2605\u2605\u2605\u2605\u2605<\/td><td>\u2605\u2605\u2605<\/td><td>\u2605\u2605\u2605<\/td><\/tr>\n<tr><td>Dynamic dry friction coefficient on steel<\/td><td>0.45<\/td><td>0.32<\/td><td>0.30<\/td><\/tr>\n<tr><td>Hygroscopicity (equilibrium)<\/td><td>2%<\/td><td>< 0.5%<\/td><td>< 0.5%<\/td><\/tr>\n<tr><td>Resilience (impact resistance)<\/td><td>High<\/td><td>Moderate<\/td><td>High<\/td><\/tr>\n<tr><td>Self-lubrication<\/td><td>Yes<\/td><td>Yes<\/td><td>Yes (structural)<\/td><\/tr>\n<tr><td>Service temperature for continuous use<\/td><td>-40\/120\u00b0C<\/td><td>-40\/90\u00b0C<\/td><td>-40\/100\u00b0C<\/td><\/tr>\n<tr><td>Chemical resistance<\/td><td>Moderate<\/td><td>Limited (strong acids)<\/td><td>Excellent<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<h2 class=\"article__h2\" id=\"glass-fiber-pa6-high-mechanical-strength-with-tribological-variables-to-manage\">\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=\"23 6 13.5 15.5 8.5 10.5 1 18\"><\/polyline><polyline points=\"17 6 23 6 23 12\"><\/polyline><\/svg><\/span>\n Glass-fiber PA6: high mechanical strength, with tribological variables to manage\n<\/h2>\n<p class=\"article__p\">Glass-fiber reinforced PA6 is the material with the highest mechanical strength among those in the catalog. Glass-fiber reinforcement increases stiffness, elastic modulus and dimensional stability, as well as the tooth’s bending strength. It’s the natural choice when transmitted torques are high and peripheral speed is contained.<\/p>\n<p class=\"article__p\">After the first run-in cycles, the glass fiber emerges on the tooth surface and can increase friction at the interface compared with standard PA6. For this reason reinforced PA6 performs best in systems at moderate speeds or with lubrication available. Some formulations include molybdenum disulfide as an internal lubricating additive: they reduce friction and improve performance under sliding conditions. If your system runs at high speed and dry, consider this option before ruling out the material.<\/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\">Calculate the meshing clearance in the “conditioned” state, that is, at moisture equilibrium. The dry-material datasheet figures don’t reflect the real in-service dimensions in humid environments.<\/p>\n<\/div>\n<p class=\"article__p\">PA6 has good resistance to oils, greases, organic solvents and alkalis: in most industrial environments it works without problems. In the presence of strong acids it’s preferable to turn to a different material.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> transmission systems with high loads and lubrication available, conveyors, pulleys, anti-wear guides, components subject to fatigue in environments that aren’t critical for moisture. In metal replacement applications it’s valued for light weight, corrosion resistance and an excellent cost\/performance ratio.<\/p>\n<h2 class=\"article__h2\" id=\"pom-c-smoothness-and-dimensional-stability-sensitive-to-impulsive-stress\">\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><line x1=\"22\" y1=\"12\" x2=\"18\" y2=\"12\"><\/line><line x1=\"6\" y1=\"12\" x2=\"2\" y2=\"12\"><\/line><line x1=\"12\" y1=\"6\" x2=\"12\" y2=\"2\"><\/line><line x1=\"12\" y1=\"22\" x2=\"12\" y2=\"18\"><\/line><\/svg><\/span>\n POM-C: smoothness and dimensional stability, sensitive to impulsive stress\n<\/h2>\n<p class=\"article__p\">POM-C occupies a completely different territory. Its highly crystalline structure gives it an intrinsically low friction coefficient and a dimensional stability that no polyamide can match. With variations below 0.2% even in humid environments, the meshing clearance calculated at the design stage stays the real one in service. This makes it the preferable choice for precision gears, actuators and compact gearmotors where positioning repeatability is a requirement.<\/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\">Above 90\u00b0C of continuous operation, the thermal stability of POM-C declines. In the presence of strong acids (pH < 4) the material undergoes rapid chemical degradation with release of formaldehyde.<\/p>\n<\/div>\n<p class=\"article__p\">The most relevant limit in transmission applications is mechanical. POM-C has a resilience, that is, the energy absorbed before fracture, significantly lower than PA6 and PK. In the presence of impulsive loads, torque peaks or abrupt starts, the tooth can fail by brittle fracture before the failure is announced by visible deformation. It’s one of the most insidious failure modes because it isn’t progressive.<\/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\">If your system involves abrupt starts or torque peaks, POM-C isn’t the right choice: brittle fracture arrives without warning.<\/p>\n<\/div>\n<p class=\"article__p\">POM-C minimizes the “<dfn id=\"def-stick-slip\"><span class=\"glossary-term\" data-tooltip=\"tt-stick-slip\" title=\"Irregular motion phenomenon characterised by alternating static adhesion and abrupt sliding between two surfaces. It generates vibrations, noise and accelerated wear.\">stick-slip<\/span><\/dfn>” effect, that is, the difference between static and dynamic friction that generates micro-oscillations. It’s a particularly useful feature where noise and motion smoothness are critical.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> compact gearmotors, precision actuators, automation in humid environments, medical devices. To be evaluated with care in the presence of high impulsive loads or temperatures above 90\u00b0C.<\/p>\n<h2 class=\"article__h2\" id=\"pk-polyketone-stable-tribological-behavior-and-high-chemical-resistance\">\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 PK (polyketone): stable tribological behavior and high chemical resistance\n<\/h2>\n<p class=\"article__p\"><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> is a semi-crystalline technopolymer that combines good mechanical strength, low friction coefficient and dimensional stability. It absorbs very little moisture: the dry-material dimensions stay valid in service too, simplifying tolerance calculations. It works well up to about 100\u00b0C and has good chemical resistance to hydrocarbons, oils and solvents.<\/p>\n<p class=\"article__p\">The dry friction coefficient of PK is 0.30. The relevant figure isn’t the number itself, but its stability over time: this tribological characteristic is an intrinsic property of the polymer chain, not an additive that wears out. PK keeps its sliding performance for the entire service life of the component. In practice, you can run dry without having to plan re-lubrication interventions, provided the peripheral speeds stay within the limits foreseen for the material.<\/p>\n<p class=\"article__p\">Chemical resistance is excellent across a wide range of solvents, acids and bases, superior to both PA6 and POM-C. Resilience is high, comparable to PA6: the risk of brittle fracture under impulsive load is reduced.<\/p>\n<p class=\"article__p\">PK has a higher raw-material cost than the other two and a still-limited availability of semi-finished products. Its adoption is justified in high-speed applications, in chemically aggressive environments, or where you want to eliminate lubrication-related maintenance entirely.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> high-speed gears running dry, transmissions in chemically critical environments, high-reliability industrial automation systems, applications where maintenance is difficult or costly.<\/p>\n<h2 class=\"article__h2\" id=\"how-to-choose-the-material-three-questions-to-orient-yourself\">\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 How to choose the material: three questions to orient yourself\n<\/h2>\n<p class=\"article__p\">Before consulting the catalogs, three questions guide the choice almost deterministically.<\/p>\n<p class=\"article__p\"> <strong>Is the load mainly static, with lubrication available?<\/strong> If the load is high and lubrication is present, glass-fiber PA6 is generally the most efficient choice for the cost\/mechanical-strength ratio. It offers good machinability and a contained cost in producing wheels and anti-wear parts.<\/p>\n<p class=\"article__p\"> <strong>Is the priority kinematic precision and quietness, with continuous operation and low torques?<\/strong> If the load is moderate and shocks are absent, POM-C generally offers the best dimensional stability and the lowest noise.<\/p>\n<p class=\"article__p\"> <strong>Does the application run at high speed and dry, in a chemically aggressive environment, or require maximum service life without maintenance?<\/strong> In these cases PK is the technically most coherent choice. The cost difference relative to the other materials should be assessed in the context of the overall TCO (total cost of ownership).<\/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\"><line x1=\"9\" y1=\"18\" x2=\"15\" y2=\"18\"><\/line><line x1=\"10\" y1=\"22\" x2=\"14\" y2=\"22\"><\/line><path d=\"M15.09 14c.18-.98.65-1.74 1.41-2.5A4.65 4.65 0 0 0 18 8 6 6 0 0 0 6 8c0 1 .23 2.23 1.5 3.5A4.61 4.61 0 0 1 8.91 14\"><\/path><\/svg>\n From the field\n <\/div>\n <p class=\"infobox__text\">In our experience, many failures on technopolymer gears come not from the wrong material, but from the operating condition not foreseen at the design stage: underestimated temperature, absent lubrication, or clearance calculated on the dry material. The right material, applied in the wrong context, doesn’t hold up.<\/p>\n<\/div>\n<div class=\"infobox\">\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=\"M4 4h16c1.1 0 2 .9 2 2v12c0 1.1-.9 2-2 2H4c-1.1 0-2-.9-2-2V6c0-1.1.9-2 2-2z\"><\/path><polyline points=\"22,6 12,13 2,6\"><\/polyline><\/svg>\n If your system’s operating conditions fall outside the standard parameters, write to us\n <\/div>\n <p class=\"infobox__text\">The technical office assesses the right configuration case by case.<\/p>\n<\/div>\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 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loads.<\/p>\n","protected":false},"parent":0,"template":"","meta":{"_acf_changed":false},"campo-applicazione":[5467],"categoria-ct":[5443],"class_list":["post-25585","centro-tecnico","type-centro-tecnico","status-publish","hentry","campo-applicazione-materials","categoria-ct-materials-and-technopolymer-selection"],"acf":[],"yoast_head":"\n<title>Choosing the Right Technopolymer for Gears | Stagnoli Gears Shop<\/title>\n<meta name=\"description\" content=\"Compare PA6, POM-C and PK for technopolymer gears, considering friction, moisture absorption, wear, dimensional stability and application limits.\" \/>\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\/choosing-the-right-technopolymer-for-gears\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" 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{"id":25585,"date":"2026-06-30T10:12:53","date_gmt":"2026-06-30T08:12:53","guid":{"rendered":"https:\/\/shop.stagnoligears.com\/?post_type=centro-tecnico&p=25585"},"modified":"2026-07-10T14:39:46","modified_gmt":"2026-07-10T12:39:46","slug":"choosing-the-right-technopolymer-for-gears","status":"publish","type":"centro-tecnico","link":"https:\/\/shop.stagnoligears.com\/en\/technical-hub\/choosing-the-right-technopolymer-for-gears\/","title":{"rendered":"Friction, moisture and wear: choosing the right technopolymer for gears"},"content":{"rendered":"\n\n \n \n \n Friction, moisture and wear: choosing the right technopolymer for gears<\/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; 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}\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-igroscopicita\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Hygroscopicity<\/div>\n <div class=\"glossary-tooltip__def\">Property of a material to absorb moisture from the surrounding environment. In technopolymers such as PA6 and PA66, it causes dimensional swelling that may reduce backlash to zero.<\/div>\n <span class=\"glossary-tooltip__tag\">Glossary<\/span>\n<\/div>\n<div id=\"tt-stick-slip\" class=\"glossary-tooltip\" hidden=\"\">\n <div class=\"glossary-tooltip__title\">Stick-slip<\/div>\n <div class=\"glossary-tooltip__def\">Irregular motion phenomenon characterised by alternating static adhesion and abrupt sliding between two surfaces. It generates vibrations, noise and accelerated wear.<\/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. 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A selection error translates into early wear, loss of kinematic precision or, in the worst cases, brittle tooth fracture.\",\n \"inLanguage\": \"en\",\n \"mentions\": [\n {\n \"@id\": \"#term-igroscopicita\"\n },\n {\n \"@id\": \"#term-stick-slip\"\n },\n {\n \"@id\": \"#term-poliketone-pk\"\n }\n ]\n },\n {\n \"@type\": \"DefinedTermSet\",\n \"@id\": \"#glossario\",\n \"name\": \"Glossario - Friction, moisture and wear: choosing the right technopolymer for gears\",\n \"hasDefinedTerm\": [\n {\n \"@type\": \"DefinedTerm\",\n \"@id\": \"#term-igroscopicita\",\n \"name\": \"Hygroscopicity\",\n \"description\": \"Property of a material to absorb moisture from the surrounding environment. 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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\">Friction, moisture and wear: choosing the right technopolymer for gears<\/h1>\n<p class=\"article__subtitle\">When designing technopolymer gears, the choice between glass-fiber reinforced PA6, POM-C and PK (polyketone) is never interchangeable. Each material answers to different tribological and environmental logics. A selection error translates into early wear, loss of kinematic precision or, in the worst cases, brittle tooth fracture.<\/p>\n<p class=\"article__p\">The critical problem is almost never tensile strength, often abundant relative to nominal loads. It’s the combination of friction coefficient, <dfn id=\"def-igroscopicita\"><span class=\"glossary-term\" data-tooltip=\"tt-igroscopicita\" title=\"Property of a material to absorb moisture from the surrounding environment. In technopolymers such as PA6 and PA66, it causes dimensional swelling that may reduce backlash to zero.\">hygroscopicity<\/span><\/dfn> and dimensional stability under cyclic load. A PA6 gear that absorbs moisture in a humid environment can change its meshing clearance enough to cause interference. A POM-C one subjected to impulsive shocks can fail by brittleness. A PK one might be more balanced, but at a cost that the application has to justify.<\/p>\n<h2 class=\"article__h2\" id=\"glass-fiber-pa6-pom-c-and-pk-where-they-truly-diverge\">\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=\"18\" y1=\"20\" x2=\"18\" y2=\"10\"><\/line><line x1=\"12\" y1=\"20\" x2=\"12\" y2=\"4\"><\/line><line x1=\"6\" y1=\"20\" x2=\"6\" y2=\"14\"><\/line><\/svg><\/span>\n Glass-fiber PA6, POM-C and PK: where they truly diverge\n<\/h2>\n<p class=\"article__p\">These three materials don’t differ by grade of quality: each governs a precise application territory, with minimal overlap.<\/p>\n<div class=\"article__table-wrap\">\n<table class=\"article__table\">\n<thead><tr><th>Property<\/th><th>PA6 + glass fiber<\/th><th>POM-C<\/th><th>PK (polyketone)<\/th><\/tr><\/thead>\n<tbody><tr><td>Mechanical strength (static load)<\/td><td>\u2605\u2605\u2605\u2605\u2605<\/td><td>\u2605\u2605\u2605<\/td><td>\u2605\u2605\u2605<\/td><\/tr>\n<tr><td>Dynamic dry friction coefficient on steel<\/td><td>0.45<\/td><td>0.32<\/td><td>0.30<\/td><\/tr>\n<tr><td>Hygroscopicity (equilibrium)<\/td><td>2%<\/td><td>< 0.5%<\/td><td>< 0.5%<\/td><\/tr>\n<tr><td>Resilience (impact resistance)<\/td><td>High<\/td><td>Moderate<\/td><td>High<\/td><\/tr>\n<tr><td>Self-lubrication<\/td><td>Yes<\/td><td>Yes<\/td><td>Yes (structural)<\/td><\/tr>\n<tr><td>Service temperature for continuous use<\/td><td>-40\/120\u00b0C<\/td><td>-40\/90\u00b0C<\/td><td>-40\/100\u00b0C<\/td><\/tr>\n<tr><td>Chemical resistance<\/td><td>Moderate<\/td><td>Limited (strong acids)<\/td><td>Excellent<\/td><\/tr><\/tbody>\n<\/table>\n<\/div>\n<h2 class=\"article__h2\" id=\"glass-fiber-pa6-high-mechanical-strength-with-tribological-variables-to-manage\">\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=\"23 6 13.5 15.5 8.5 10.5 1 18\"><\/polyline><polyline points=\"17 6 23 6 23 12\"><\/polyline><\/svg><\/span>\n Glass-fiber PA6: high mechanical strength, with tribological variables to manage\n<\/h2>\n<p class=\"article__p\">Glass-fiber reinforced PA6 is the material with the highest mechanical strength among those in the catalog. Glass-fiber reinforcement increases stiffness, elastic modulus and dimensional stability, as well as the tooth’s bending strength. It’s the natural choice when transmitted torques are high and peripheral speed is contained.<\/p>\n<p class=\"article__p\">After the first run-in cycles, the glass fiber emerges on the tooth surface and can increase friction at the interface compared with standard PA6. For this reason reinforced PA6 performs best in systems at moderate speeds or with lubrication available. Some formulations include molybdenum disulfide as an internal lubricating additive: they reduce friction and improve performance under sliding conditions. If your system runs at high speed and dry, consider this option before ruling out the material.<\/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\">Calculate the meshing clearance in the “conditioned” state, that is, at moisture equilibrium. The dry-material datasheet figures don’t reflect the real in-service dimensions in humid environments.<\/p>\n<\/div>\n<p class=\"article__p\">PA6 has good resistance to oils, greases, organic solvents and alkalis: in most industrial environments it works without problems. In the presence of strong acids it’s preferable to turn to a different material.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> transmission systems with high loads and lubrication available, conveyors, pulleys, anti-wear guides, components subject to fatigue in environments that aren’t critical for moisture. In metal replacement applications it’s valued for light weight, corrosion resistance and an excellent cost\/performance ratio.<\/p>\n<h2 class=\"article__h2\" id=\"pom-c-smoothness-and-dimensional-stability-sensitive-to-impulsive-stress\">\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><line x1=\"22\" y1=\"12\" x2=\"18\" y2=\"12\"><\/line><line x1=\"6\" y1=\"12\" x2=\"2\" y2=\"12\"><\/line><line x1=\"12\" y1=\"6\" x2=\"12\" y2=\"2\"><\/line><line x1=\"12\" y1=\"22\" x2=\"12\" y2=\"18\"><\/line><\/svg><\/span>\n POM-C: smoothness and dimensional stability, sensitive to impulsive stress\n<\/h2>\n<p class=\"article__p\">POM-C occupies a completely different territory. Its highly crystalline structure gives it an intrinsically low friction coefficient and a dimensional stability that no polyamide can match. With variations below 0.2% even in humid environments, the meshing clearance calculated at the design stage stays the real one in service. This makes it the preferable choice for precision gears, actuators and compact gearmotors where positioning repeatability is a requirement.<\/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\">Above 90\u00b0C of continuous operation, the thermal stability of POM-C declines. In the presence of strong acids (pH < 4) the material undergoes rapid chemical degradation with release of formaldehyde.<\/p>\n<\/div>\n<p class=\"article__p\">The most relevant limit in transmission applications is mechanical. POM-C has a resilience, that is, the energy absorbed before fracture, significantly lower than PA6 and PK. In the presence of impulsive loads, torque peaks or abrupt starts, the tooth can fail by brittle fracture before the failure is announced by visible deformation. It’s one of the most insidious failure modes because it isn’t progressive.<\/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\">If your system involves abrupt starts or torque peaks, POM-C isn’t the right choice: brittle fracture arrives without warning.<\/p>\n<\/div>\n<p class=\"article__p\">POM-C minimizes the “<dfn id=\"def-stick-slip\"><span class=\"glossary-term\" data-tooltip=\"tt-stick-slip\" title=\"Irregular motion phenomenon characterised by alternating static adhesion and abrupt sliding between two surfaces. It generates vibrations, noise and accelerated wear.\">stick-slip<\/span><\/dfn>” effect, that is, the difference between static and dynamic friction that generates micro-oscillations. It’s a particularly useful feature where noise and motion smoothness are critical.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> compact gearmotors, precision actuators, automation in humid environments, medical devices. To be evaluated with care in the presence of high impulsive loads or temperatures above 90\u00b0C.<\/p>\n<h2 class=\"article__h2\" id=\"pk-polyketone-stable-tribological-behavior-and-high-chemical-resistance\">\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 PK (polyketone): stable tribological behavior and high chemical resistance\n<\/h2>\n<p class=\"article__p\"><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> is a semi-crystalline technopolymer that combines good mechanical strength, low friction coefficient and dimensional stability. It absorbs very little moisture: the dry-material dimensions stay valid in service too, simplifying tolerance calculations. It works well up to about 100\u00b0C and has good chemical resistance to hydrocarbons, oils and solvents.<\/p>\n<p class=\"article__p\">The dry friction coefficient of PK is 0.30. The relevant figure isn’t the number itself, but its stability over time: this tribological characteristic is an intrinsic property of the polymer chain, not an additive that wears out. PK keeps its sliding performance for the entire service life of the component. In practice, you can run dry without having to plan re-lubrication interventions, provided the peripheral speeds stay within the limits foreseen for the material.<\/p>\n<p class=\"article__p\">Chemical resistance is excellent across a wide range of solvents, acids and bases, superior to both PA6 and POM-C. Resilience is high, comparable to PA6: the risk of brittle fracture under impulsive load is reduced.<\/p>\n<p class=\"article__p\">PK has a higher raw-material cost than the other two and a still-limited availability of semi-finished products. Its adoption is justified in high-speed applications, in chemically aggressive environments, or where you want to eliminate lubrication-related maintenance entirely.<\/p>\n<p class=\"article__p\"><strong>Recommended applications:<\/strong> high-speed gears running dry, transmissions in chemically critical environments, high-reliability industrial automation systems, applications where maintenance is difficult or costly.<\/p>\n<h2 class=\"article__h2\" id=\"how-to-choose-the-material-three-questions-to-orient-yourself\">\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 How to choose the material: three questions to orient yourself\n<\/h2>\n<p class=\"article__p\">Before consulting the catalogs, three questions guide the choice almost deterministically.<\/p>\n<p class=\"article__p\"> <strong>Is the load mainly static, with lubrication available?<\/strong> If the load is high and lubrication is present, glass-fiber PA6 is generally the most efficient choice for the cost\/mechanical-strength ratio. It offers good machinability and a contained cost in producing wheels and anti-wear parts.<\/p>\n<p class=\"article__p\"> <strong>Is the priority kinematic precision and quietness, with continuous operation and low torques?<\/strong> If the load is moderate and shocks are absent, POM-C generally offers the best dimensional stability and the lowest noise.<\/p>\n<p class=\"article__p\"> <strong>Does the application run at high speed and dry, in a chemically aggressive environment, or require maximum service life without maintenance?<\/strong> In these cases PK is the technically most coherent choice. The cost difference relative to the other materials should be assessed in the context of the overall TCO (total cost of ownership).<\/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\"><line x1=\"9\" y1=\"18\" x2=\"15\" y2=\"18\"><\/line><line x1=\"10\" y1=\"22\" x2=\"14\" y2=\"22\"><\/line><path d=\"M15.09 14c.18-.98.65-1.74 1.41-2.5A4.65 4.65 0 0 0 18 8 6 6 0 0 0 6 8c0 1 .23 2.23 1.5 3.5A4.61 4.61 0 0 1 8.91 14\"><\/path><\/svg>\n From the field\n <\/div>\n <p class=\"infobox__text\">In our experience, many failures on technopolymer gears come not from the wrong material, but from the operating condition not foreseen at the design stage: underestimated temperature, absent lubrication, or clearance calculated on the dry material. The right material, applied in the wrong context, doesn’t hold up.<\/p>\n<\/div>\n<div class=\"infobox\">\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=\"M4 4h16c1.1 0 2 .9 2 2v12c0 1.1-.9 2-2 2H4c-1.1 0-2-.9-2-2V6c0-1.1.9-2 2-2z\"><\/path><polyline points=\"22,6 12,13 2,6\"><\/polyline><\/svg>\n If your system’s operating conditions fall outside the standard parameters, write to us\n <\/div>\n <p class=\"infobox__text\">The technical office assesses the right configuration case by case.<\/p>\n<\/div>\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 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loads.<\/p>\n","protected":false},"parent":0,"template":"","meta":{"_acf_changed":false},"campo-applicazione":[5467],"categoria-ct":[5443],"class_list":["post-25585","centro-tecnico","type-centro-tecnico","status-publish","hentry","campo-applicazione-materials","categoria-ct-materials-and-technopolymer-selection"],"acf":[],"yoast_head":"\n<title>Choosing the Right Technopolymer for Gears | Stagnoli Gears Shop<\/title>\n<meta name=\"description\" content=\"Compare PA6, POM-C and PK for technopolymer gears, considering friction, moisture absorption, wear, dimensional stability and application limits.\" \/>\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\/choosing-the-right-technopolymer-for-gears\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" 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