(BA) screw British Association

X150
1

BA thread, British Association, machine screw used on Lucas electrics, Smith Instrument, trim and all pre 1960 Jaguars. Numbers range for 1BA Smallest to 10BA the largest. Jaguar Parts manual will list #BA + the second number is the lengths in1/8 of an inch. ie: 2BA 4 is(4 X 1/8 or1/2 inch long, 6BA 2 is 1/4 inch long. 4BA 1 is 1/8inch long.
A good source for BA (machine screws), Whitworth (course),and BSF (British Standard Fine) is British Tool & Fastener. they also have taps, dies and tools.
etypefun@pacbell.net

2

Hi;
I don’t want to be picky but BA threads are the other way round - 0BA largest at 0.2360 inches diameter,1BA 0.2090", diameter then reducing in size as their reference number increases - e.g 10BA 0.067".Theoretically they go as small as 16BA which is 0.0310" dia but 10BA is probably the limit for practical purposes.

David

3

Learn a fact a day: never knew what the “BA” represented!

4

thanks, for my obvious inverse error.

5

thanks, my obvious error.