3/8" x 19 BSPF HSS Tap Set - Goliath HSS Bright Finish BSPF Hand and Machine Tap Set. Pipe taps are much shorter than a similar size of regular hand tap, but the design features are the same. Goliath HSS taps provide a high hardness to toughness ratio, compressive and tensile strength, good abrasion resistance and resistance to micro-chipping, ensuring a long tool life. British Standard Pipe - G Series (BSPF) 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. Intermediate Taps have a lead of four threads and are used in most general purpose applications to cut a thread true to a pre-drilled pilot hole. Bottoming Taps have a lead of two threads and are used to ensure minimum thread run-out when tapping to the bottom of a blind hole. Bottoming Taps are typically preceded by the use of a Taper or Intermediate Tap. Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.for hand or general machine use.