This document specifies definitions, dimensions and tolerances of parallel screw threads of M30 x 2, M25 x 2 and M18 x 1,5, for the connection of valves to medical and industrial gas cylinders.

This document does not contain the connection requirements for:

—    mechanical strength;

—    gas tightness;

—    capability of repeated assembly and dismounting operations (this aspect is covered in ISO 13341).