NBN ISO 529:2021

This document specifies the general dimensions of short machine taps and hand taps. These dimensions,
established as functions of the thread diameter and pitch, are the following:
— length of thread (maximum);
— overall length;
— shank diameter and dimensions of driving square;
— dimensions of the connecting portion between the shank and threaded part.
This document is applicable to taps intended for cutting the following threads:
a) ISO metric threads:
— coarse pitch;
— fine pitch;
b) ISO inch threads:
— “Unified Coarse” series (UNC) and “Unified Fine” series (UNF);
c) Inch threads, non-recommended:
— “British Standard Whitworth” (BSW) and “British Standard Fine” (BSF);
— “British Association” (BA).
NOTE 1 The overall length, thread length and diameters of shank for taps whose thread diameter and pitch
are not listed in tables are given in Table A.1.
NOTE 2 Annex B gives an abstract from ISO 237 for shank diameters and size of driving squares, for
information.
NOTE 3 Technical specifications for taps covered by this document (including marking) are given in ISO 8830.