When measuring the thread pitch, use the tooth-shaped steel plate in the pitch gauge as a template and clamp it to the threaded part. If it doesn't fit properly, replace it with another piece until it snaps into place. At this point, the size indicated on the pitch gauge is the pitch of the threaded part to be measured.^ However, it should be noted that when the pitch gauge is stuck on the profile of the thread, the length of the working part of the thread should be used as much as possible to make the measurement result more accurate.^ When measuring the angle of the profile, place a thread gauge with the same pitch as the threaded part on the thread to be tested, then check the contact between the two.^ If there is no space for light transmission, the profile angle of the tested thread is correct. If there is transmission of light through uneven spaces, it means that the profile of the wire to be tested is not accurate. This measurement method is very approximate.