I have a 1944 bsa m20. Had to replace the clutch push plate with a new one. The studs that are welded on are larger than the originals and I can't figure out what size they are. A 5/16" nut with bsc thread is too large, and I don't think a 1/4" nut will fit. Tried a M7 nut and it looks to be the right size but the thread pattern is off. Please help

email (option): jeff@infinitymedspa.com

Hi Jeff...nominal size of a 1/4 thread is .250", a 5/16 thread .312". 7mm (which is an unusual size) equates to approx .276".
The largest BA thread is 0BA at .236" so that rules that out.
Can you measure the outside diameter of the thread you have and more importantly determine the number of threads per inch?
Carefully count the FULL threads over a 1/4 or better, a 1/2 inch length and multiply that up.
With that information it should be possible to identify what you have...Ian

the outside diameter is 7mm exactly. I will count the threads tonight. I appreciate the help.

email (option): jeff@infinitymedspa.com