Why does nobody talk about annealing blade blanks before drilling?

I was at a hammer-in down in Springfield last month, watching this old guy drill perfect holes in a 1084 blank like it was butter. Meanwhile I was over there burning through my third cobalt bit on a piece of 1095. He just walked over and said 'you gotta take the stress out first, kid.' Took me about 20 minutes to realize he was talking about annealing that area around where you drill. I always just went straight to drilling after heat treat thinking it was fine. Turns out throwing it in the forge for a quick cycle at like 1200 degrees and letting it cool slow makes a massive difference. Now I do that on every blade before I even think about putting a bit to it. Has anyone else figured this out the hard way?

3 comments

3 Comments

joelh641mo ago

Funny enough I've got a little shrine of broken drill bits on my shelf too... wallet hurts just looking at it.

amy_foster791mo ago

Ain't that the truth? I learned this one the hard way too, snapped so many bits I started thinking I was getting scammed at the hardware store. The worst was when I spent a whole afternoon trying to drill a 5/32 hole in a piece of O1 that was practically smoking, and it eventually walked off and ruined the whole blank. Now I just do a quick heat to non-magnetic and let it cool in the ashes, and it's like night and day difference. I still keep a box of busted bits on my workbench as a reminder of my younger, dumber days.

oliver_morgan18d ago

Man, I dunno. I've drilled plenty of blades straight from heat treat and never had that much trouble. Maybe you're just using bad bits?