Use as a reference tool in determining the pitch of a thread that is on a screw, nut, fastener or in a tapped hole. Saves time, in that it, removes the need to measure and calculate the thread pitch of the threaded item. Measures thread counts from 4 to 42 SAE and .25 to 6.0mm. Measures thread counts from 4 to 42 SAE and .25 to 6.0mm. 60 degree thread profiles and locking devices.