Tapping Drill Sizes for BSW Threads

The following tables show the range of drill sizes suitable for tapping BSW (British Standard Whitworth) screw threads.

The first table gives general information about BSW threads - the thread angle, and, for each size, the nominal diameter and thread pitch.

Please also read the general comment on the Tapping Index page.

BSW table BSW tapping 1 BSW tapping 2 BSW tapping 3 BSW tapping 4 BSW tapping 5 BSW tapping 6 BSW tapping 7 BSW tapping 8 BSW tapping 9