Originally Posted by
Geoff555
Hello thank you, the bolt measures .165" ish, oval and worn. TPI , fine, impossible to count as there is nothing left. Sorry but I could not find the thread on the BSA forum, will try again.
Cheers.
Geoff.
Really old BSA used "Bicycle Thread" bolts, but I think in your case they would be using BA which is an obsolete set of threads up to 0BA (around 6mm). Yours is probably a worn 2BA 0.185 inch dia 31.36 TPI. If not it will be 3BA 0.1614 inch dia 34.79 TPI. These bolts are still available, also taps and dies. I have worked on old Webleys that use BSF threads and there is the smallest, 3/16 - 0.1675 inch dia 32 TPI.
Baz
Last edited by Benelli B76; 03-07-2017 at 06:45 AM.
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