TAP AND DIE SET BRITISH STANDARD WHITWORTH- BOXED COMPLETE BSW 1/4 3/4 ALPS. British Standard Whitworth (BSW) is one of a number of imperial unit based screw thread standards which use the. Same hexagonal bolt head and nut sizes. NO OF SIZE: 07 (1/4" TO 3/4" BSW).
SIZES: 1/4", 5/16", 3/8", 7/16", 1/2", 5/8", 3/4, BSW.