Square hole

[PJs]

This young man makes a square broach and makes it look so easy.

Chris (Clipspring) makes it look easy for sure but he is broaching brass. Simple but effective but on brass, not sure how the hardened 01 (silver steel) would hold up on steel. But if you only need one...might work. I might consider the hole and broach method with a good hardened tool like Toolmaker51 suggests in your mill spindle.

~PJ