Specifications of historical Thread Standards

Attention!

Please do not mistake this thread for the Whitworth Fine Thread BS 84. This thread is an old one which is not used anymore. The nominal diameter and the pitch are mentioned in millimeters or in TPI.
Used in locomotive construction approx. until 1975.
The flank angle is 55°.

Diameter for bolt and nut
Thread SizeTapping Drill Size
mm
Core Area
cm2
TPIPitch
mm
W 20 x 1/10" LON16.7462.20102.54
W 23 x 1/10" LON19.7463.06102.54
W 26 x 1/10" LON22.7464.06102.54
W 30 x 1/10" LON26.7465.62102.54
W 33 x 1/10" LON29.7466.95102.54
W 34 x 1/10" LON30.7467.42102.54
W 36 x 1/10" LON32.7468.42102.54
W 37 x 1/10" LON33.7468.94102.54
W 40 x 1/10" LON36.74610.60102.54
W 42 x 1/10" LON38.74611.78102.54
W 43 x 1/10" LON39.74612.41102.54
W 46 x 1/10" LON42.74614.35102.54
W 50 x 1/10" LON46.74617.16102.54
W 53 x 1/10" LON49.74619.44102.54
W 56 x 1/10" LON52.74621.85102.54
W 60 x 1/10" LON56.74625.29102.54
W 63 x 1/10" LON59.74628.04102.54
W 66 x 1/10" LON62.74630.92102.54
W 70 x 1/10" LON66.74634.99102.54
W 73 x 1/10" LON69.74638.21102.54
W 76 x 1/10" LON72.74641.56102.54
W 80 x 1/10" LON76.74646.26102.54
Whitworth Fine Thread DIN 286