Spring Clamp - for slotting balance weights and hairspring collet
A strip of 1/8" brass plate and 1/32" O-1 steel plate were sawed out. They were clamped to together and drilled 1.25mm for tapping for a 1.5mm screw and for steady pins.
A 1.5mm screw was turned from 4mm O-1 drill rod. The details for making this particular screw was used as the example at the end of the screwhead polishing jig page. The steel plate is broached to clear the screw. The pins are loosely fit in the steel plate and the brass strip broached to fit the pins. The clamp has two working sides, one will be drilled for holding the balance weights and the other will be drilled for holding and slotting the hairspring collet later on.
The brass strip is setup on the lathe for slotting with a 0.012" slitting saw. The steel piece is reattached and sawn itself.
The corners are filed down. The steel piece is then hardened in oil, repolished, and then blued to the spring state. It is then polished to its final form.