logo

Standards Manage Your Business

We Manage Your Standards

ISO

ISO 21771-2:2025

Cylindrical involute gears and gear pairs — Part 2: Calculation and measurement of tooth thickness and backlash

Standard Details

This document establishes the calculation procedures for determining specification limits for external and internal cylindrical involute gearing with constant gear ratio when the desired tooth thickness is known. It also shows the relationships between backlash and the tooth thickness, centre distance, and tooth deviations in a pinion and gear mesh.

This document applies to the following types of gears:

     external and internal parallel axis cylindrical involute spur and helical gears;

     involute worms and crossed axis gears;

     spur and helical racks;

     involute spur and helical sector gears.

The formulae in this document apply to gears of all sizes and materials, and to all manufacturing methods.

This document does not provide guidance on selecting the tooth thickness or the tolerance on the thickness.

General Information

Status : Published
Standard Type: Main
Document No: ISO 21771-2:2025
Document Year: 2025
Pages: 140
Edition: 1

Life Cycle

Currently Viewing

Published
ISO 21771-2:2025
Knowledge Corner

Expand Your Knowledge and Unlock Your Learning Potential - Your One-Stop Source for Information!

© Copyright 2026 BSB Edge Private Limited.

Enquire now +