Chrome Alloy BSW Hand Tap Set This thread form was developed by Sir Joseph Whitworth in British Standard Whitworth has a thread angle of 55 degrees
Chrome Alloy BSW Hand Tap Set. British Standard Whitworth has a thread angle of 55 degrees as opposed to 60 degrees in Metric and Unified threads. Chrome alloy taps are not suitable for creating precision, safety or critical threads. Used as thread chasers to clean an existing thread, making it a reliable machine tap set.
