This series is a pipe thread which is used mainly for mechanical coupling. The angle of thread is mainly 55° however for the US method some threads have a 60° angle. It is specified according to JIS and ISO R228.
TAPER TAPS have a lead of eight threads and are used as a starting tap in difficult or high precision holes.
Manufactured from premium chrome alloy steel this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.