HDT (Heat Deflection Temperature)
Temperature at which a standard polymer specimen undergoes a defined flexural deflection under a constant load. It indicates the thermal operating limit of the material.
Technical Reference
Technical Gear Glossary
Definitions of the main technical terms used in motion transmission with technopolymer gears.
H
Helix angle
Angle formed by the tooth helix with respect to the gear axis. In spur gears it is 0°; in helical gears it typically ranges between 8° and 20°.
Hybrid coupling
Structural design solution combining a metal hub with a technopolymer gear ring. Merges the structural strength of metal with the tribological and damping properties of the polymer.
Hygroscopicity
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.