Tap - Tolerances

Representation of tap tolerances as a diagram

Legend

Pitch diameter tolerance of internal thread acc. DIN ISO 965-1

Taps with specific pitch diameter tolerance

Pitch diameter tolerance of the tap acc. DIN EN 22857

Pitch diameter tolerance of the no-go thread plug gauge acc. DIN ISO 1502

Pitch diameter tolerance of the go thread plug gauge acc. DIN ISO 1502

EI

Basis

t

Tolerance class 5 of the internal thread (tol. unit)

TD2

Pitch diameter tolerance

Tolerance class of taptolerance field internal threadRemarksApplications
4H (DIN 802/1)ISO 14H5H   UndersizeThreaded connections with little play
6H (DIN 802/1)ISO 24G5G6H  NormalNormal threaded connection
6G (DIN 802/1)ISO 3  6G7H8HOversizeThreaded connections with a lot of play
7G (DIN 802/4)    7G8GOversizebefore heat treatment leading to distortion
6H +0,1      Oversizegalvanic surface treatment w. Layer thickness ≈ 25μm
6H +0,2      Oversizegalvanic surface treatment w. Layer thickness ≈ 50μm