GB/T 2363-2025 in English

《GB/T 2363-2025小模数渐开线圆柱齿轮精度》由TC52（全国齿轮标准化技术委员会）归口，主管部门为国家标准委。

Scope

This document specifies eight tolerance grades (Grades 4 to 11) from smallest to largest, and the tolerances for each tolerance grade are calculated using formulas (1) to (9). The applicable ranges for these formulas are as follows: 0.1 mm ≤ mₙ < 0.5 mm; 5 ≤ z ≤ 200; 0.5 mm ≤ d ≤ 100 mm; 0.2 mm ≤ b ≤ 10 mm; β ≤ 45°. When the normal module (mₙ) of an involute cylindrical gear is less than 0.1 mm, the tooth surface accuracy grade and tolerance value setting may be referenced in this document, but this is subject to negotiation between the supplier and the purchaser only.