Chainsaw Repair

That sounds like a much more simple method than carving out a new tip .

Hardening steel isn't a big deal though .You use some alloy of steel like 4140 ,A2,O2 or some other steel that has enough carbon to harden .Heat it up until it's about the color of a pumpkin and toss it in a bucket of oil .

There are methods of hardening mild steel but that's a little off of topic .

Probabley a grade 8 cap screw would be hard enough for a punch but the roller bearing is still more simple .

I don't own a punch my self .Just grind the rivet heads off and seperate the link with a thin chisel ----old school ya know .