GB/T 10227-2025 Active

This document specifies the accuracy system, tolerances, inspection rules, and drawing marking requirements for small-module cylindrical worms, worm wheels (or helical gears), and worm gear sets. This document applies to cylindrical worm and worm wheel sets with a module m of 0.1 mm to 0.5 mm and an axial angle ∑ of 90°. Among them, the worm pitch circle diameter d₁ is ≤30 mm, and the worm wheel pitch circle diameter d₂ is ≤320 mm. The worm types include Archimedean worms (ZA), involute worms (ZI), normal straight profile worms (ZN), and conical envelope worms (ZK). This document also applies to worm-gear sets composed of involute worms (ZI) and involute helical gears. Note: In this document, small-module cylindrical worms and small-module cylindrical worm wheels are respectively referred to as "worms" and "worm wheels". Small-module involute helical gears are referred to as "helical gears". Small-module cylindrical worm and worm wheel sets are collectively referred to as "worm gear sets". Small-module involute cylindrical worm and involute helical gear sets are collectively referred to as "worm-gear sets".