Pipe Thread Plug Gauge：Pipe threads are divided into parallel thread gauges and taper thread gauges. Parallel pipe thread gauges have passing side and stopping side make up a single set. The thread is considered to be acceptable if the passing side passes with ease and the stopping side does not cut in after two rotations. According to the requirements of different specifications, there are some differences in the codes of the GO and NOGO , such as the GP-NP of the ISO standard or the GP-WP(IP) of the JIS standard. The pipe taper thread ring gauges are cut at the reference path position and screwed into the stop position to determine whether the size meets the standard. For different specification types, there are some differences in appearance and measurement methods of taper pipe thread ring gauges. For example, the specification of PT has sliced with 1 step, and the NPT has sliced with 3 steps (MIN. BASIC.MAX).
