7/16 x 19 tpi tap, and die

[MARK RIGG]

There is a useful chart on the Internet - `A COMPLIATION OFTHREAD SIZE INFORMATION ` which lists all thread diameters
pitches , etc, etc .

7/16 x 19 tpi is not listed - could this be a case of mistaken tpi measurement - could it not be 18 tpi ? .

7/16 x 18 is BSF and I would have thought a pre- war Austin 7 would have used all BSF threads where possible.

The only other alternative is 7/16 x 20 tpi which UNF - that would not have been in common useage of that period Austin.

MARK