scope:

This Standard establishes a tolerance classification system relevant to manufacturing and conformity assessment of tooth flanks of individual cylindrical involute gears. It specifies definitions for gear flank tolerance terms, the structure of the flank tolerance class system, and allowable values. Eleven flank tolerance classes are defined, numbered 1 to 11. Formulae for tolerances are provided in 6.3. These tolerances are applicable to the following ranges:

5 ≤ z ≥ 1 000

5 mm ≤ d ≥ 15 000 mm

0.5 mm ≤ m_n ≤ 70 mm

4 mm ≤ b ≤ 1 200 mm

β ≤ 45°

where,

d is the reference diameter (see JIS B 0102-1);

m_n is the normal module;

b is the facewidth (axial);

z is the number of teeth;

β is the helix angle.

Surface texture is not considered in this Standard. For additional information on surface texture, see ISO/TR 10064-4.

NOTE: The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows.

ISO 1328-1: 2013 Cylindrical gears-ISO system of flank tolerance classification- Part 1: Definitions and allowable values of deviations relevant to flanks of gear teeth (MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/lEC Guide 21-1.