BS ISO 1501:2009+A1:2020

This standard BS ISO 1501:2009+A1:2020 ISO miniature screw threads is classified in these ICS categories:

• 21.040.30 Special screw threads

This International Standard specifies the profiles, diameter-pitch combinations, basic dimensions, tolerances, limits of size and designation for ISO miniature screw threads with nominal diameters from 0,3 mm to 1,4 mm. These threads are applicable to timepieces, optical instruments, electrical meters, measuring instruments, etc.

The profiles and tolerance system for ISO miniature screw threads (S) differ from the profile and tolerance system for ISO general purpose metric screw threads (M).

For threads with nominal diameters from 1 mm to 1,4 mm, designers shall decide to use ISO general purpose metric screw threads (M) or ISO miniature screw threads (S). ISO miniature screw threads are shown in Annex A.

Annex C illustrates the differences in miniature screw threads between the ISO International Standards and those of certain countries.