Tools & Gear Taps & Dies HSS Hand and Machine Taps

BSWBRITISH STANDARD WHITWORTH The angle of thread is 55 degrees as opposed to 60 degrees in Metric and Unified threads. This thread form was developed by Sir Joseph Whitworth in 1841. The thread form has rounded roots and crests and is specified in BS84:1956. TAPER TAPS have a lead of eight threads and are used as a starting tap in difficult or high precision holes. Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.