Tools & Gear Taps & Dies Chrome Alloy 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. 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.