I walked past the Peerless Crankcase a day or two ago and of course, the 1/2" studs which hold the cylinders to it are still screwed in it, and they caught my eye. I assumed that the thread on those would be either 1/2" Whit or 1/2" UNC - it would have been but unlikely, I thought, but maybe 1/2" BSF or 1/2" UNF. Following my earlier confusion with the BSB thread on the Cam Followers and Tappets, I thought that I would check those studs! And guess what - they are 18 tpi - so none of the aforementioned threads!
Any thoughts on that one, please?
Tony