Posted by Speedy Builder5 on 17/08/2016 13:51:58:
Nice nuts Andrew. I never knew that BSF/BSW was so rare that you had to make em.
Thanks Bob, but they're not rare, it's just that the commercial ones don't come anywhere near the standard I expect. I did buy some cheap commercial 1/4" BSF bolts and nuts but they simply didn't 'measure' up. They're now relegated to jigs and fixtures. The nuts, and locknuts, are based on the old Whitworth standards, although the AF dimension was determined by the hex collets I have, and in the case of the 5/16" BSF nuts the available space on the cylinder casting.
Of course having a repetition lathe helps, once set up it is easy to churn out parts quickly. All the nuts shown only took a few hours over a few evenings. And all done with freehand ground HSS tooling, not a jig in sight. 
I've also made my own BSF studs and bolts. These are all highly visible parts of the engine, on the cylinder block and motion work, so I want them to stand out. And it allows you to get one over on the rivet counters. 
Andrew