ISO International Standard

ISO 16239:2013 specifies the material, metric series nominal diameters, diameter tolerances, and designation for screw thread measuring wires.

ISO 16239:2013 is applicable to measure 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 mainly used to calibrate the pitch diameters of thread plug gauges.