Qualtech DWTBSPS1/8 1/8" BSPS HSS Straight Pipe Taps

British Standard Whitworth Thread, after its introduction in 1841, was rapidly adopted throughout England and the continent. British Standard Fine Thread is a second series which was established in 1908 to meet the needs of additional engineering activity. The thread angle for BSW and BSF is 55, whereas the thread angle for all standard NC, NF, NPT, etc. is 60. During 1975, the British formally completed their ten year conversion to the metric system, thus making the British thread forms and inch measurements obsolete for new design and production.