06-11-2017, 10:58 AM
(This post was last modified: 06-11-2017, 11:02 AM by Dennis Nicholas.)
According to Newnes Engineer's Reference Book (sixth edition 1954)
Admiralty fine thread (Obsolete) Whitworth Form) 5/8 is 20 Tpi.
British Standard Whitworth 55 degree angle 5/8 is 11 Tpi. (Whitworth form threads).
British Standard Fine 55 degree 5/8 is 14 Tpi. (Whitworth form threads)
So it seems we have established that the Herbert Austin threads were 5/8 16 Tpi (with a Whitworth 55 degree form ???)(that is with rounded tops and bottoms to the threads).
BSW, BSF and now Perhaps we could have HAT (Herbert Austin Thread)
Admiralty fine thread (Obsolete) Whitworth Form) 5/8 is 20 Tpi.
British Standard Whitworth 55 degree angle 5/8 is 11 Tpi. (Whitworth form threads).
British Standard Fine 55 degree 5/8 is 14 Tpi. (Whitworth form threads)
So it seems we have established that the Herbert Austin threads were 5/8 16 Tpi (with a Whitworth 55 degree form ???)(that is with rounded tops and bottoms to the threads).
BSW, BSF and now Perhaps we could have HAT (Herbert Austin Thread)