scope:

This International Standard specifies the material, metric series nominal diameters, diameter tolerances, and designation for screw thread measuring wires.

This International Standard is applicable to the measurement of the pitch diameters of ISO general purpose metric screw threads (M), Unified screw threads (UN), Whitworth pipe threads (G, R), and ISO metric trapezoidal screw threads (Tr) with standard pitches. These wires are intended for use on screw threads with a small lead angle, less than 5°, and are mainly used to calibrate the pitch diameters of thread plug gauges.