Description
DESCRIPTION BSW (British Standard Whitworth) Chrome Alloy Hand Taps 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. The thread angle for BSW is 55° as opposed to 60° in Metric and Unified threads. 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. REVIEWS
