British Screw Pitch Gauges

A screw pitch gauge is the perfect tool to identify exact TPI or pitch.

BSP, BSPT, BSW, BSF & BSB threads have 55° pitch angle.
BA threads have 47.5° pitch angle

SPG 0-10 BA (12 leaves) 0 1 2 3 4 5 6 7 8 9 10 & 47.5° angle leaf

SPG BSP (6 leaves) 8 10 11 14 19 28

SPG M-BSP (7 leaves) Metric- 1.0 1.5 2.0   BSP- 11 14 19 28

SPG W4-62 (28 leaves) 4 4.5 5 6 7 8 9 10 11 12 13 14 16 18 19 20 22 24 25 26 28 30 32 36 40 48 60 62

SPG WM52 0.25-6.0mm & 4-62 TPI 55° Whitworth (52 leaves) Metric- .25. 3 .35 .4 .45 .5 .6 .7 .75 .8 .9 1.0 1.25 1.5 1.75 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
Whitworth- 4 4.5 5 6 7 8 9 10 11 12 13 14 16 18 19 20 22 24 25 26 27 28 30 32 36 38 40 48 60 62