by matthewh » Mon Sep 22, 2014 7:33 pm
Irwin isn't bad, I've used and abused there larger drill bits, and they've held up ok. Biggest issue I've had with hole saws threw steel, is getting them to cut slow. I usually use a dewalt 1/2" chuck drill, the big amp one, and have a hard time getting the speed down low enough to cut good, and keep enough airflow into the drill. Usually I drill till its too hot to hold onto with gloves, and set it in front of a fan, let it cool, repeat.
I've hole sawed 1/4" plate steel before, just takes time.
'93 W350 5spd Getrag, 4.10 gears, 83k miles and counting, Mods: LPPP AKA Ma Dually
'54 Dodge M37 6.2/700R4/205, 5.89 gears, WC rear axle