A brass hexagonal 27 mm bar gives the necessary material, it had been used as a chisel or something as the end part's been completely deformed by a hammer's numerous hits.
The center part's still red hot of the light saber cut (a reflection of the very rare sun in my workshop on a red plastic can).
Using an équerre à centrer (centering square) to mark the place to drill the central hole.
Makes so nice chips !
Trying to mill, it's long, not the appropriate bit for the shape needed.
Hand filling's faster and doesn't make noise, vibrations, and gives my arms and hands a good exercise.
First a tough file, and a smoother, and a much smoother, and sand paper, from 400 to 2000 grain, brass is very pleasant to work with.
It'll give a good grip.
It needs a shoulder, in the center, the head size's perfect.
Milling is easy.
Not very fast but not too long.
A little filling, to have a nice rond shape.
And that's it : a completely home made 3/8 " screw with its tightening nut.
The second one was faster to achieve and has a nice guilloché finish.