steel too hard to drill

4

440-c

Joined
Apr 21, 2012
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19
i have made a billet of 1084 and 15N20 304 count layers. 2x2x9". I normalized it twice then band sawed the blades out, seemed fine. Drill milled them to even thickness then surfaced finished. Did the first grind of edges and got all scratches out to 120 grit. went to drill holes and couldn't do all the holes(too hard). my question is why and how do I remedy this problem. Can you get the steel too hot when grinding and makes it hard again? Should I normalize or anneal? Best thoughts Please. Thanks
 
I'd suspect work hardening. Anneal.

How's your drill bit? I'd see if it needs some maintenance, if there's any question that it could be in need.
 
Carbide drill bits will penetrate hardened steel. I've drilled several finished and fully hardened blades with carbide bits without difficulty.
 
killgar said:
Carbide drill bits will penetrate hardened steel. I've drilled several finished and fully hardened blades with carbide bits without difficulty.
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I've read that a hardened steel chip should be blue, not brown/black on the one hand (too much heat) or silver on the other. But if the chips are blue, doesn't that mean the surrounding steel is getting pretty hot? Will drilling holes in hardened steel mess with the heat treat / hardness?
 
if I anneal and get the holes drilled do I need to normalize the steel a couple of times to be ready for hardening?
 
Solid carbide drills drill hard steel easy peasy.

However, it's super easy to snap a twenty five dollar drill bit.

You can sharpen carbide tipped masonry drills with the diamond wheel on Drill Doctors.
run them slow enough that you don't melt the solder holding the carbide on.


Or get some solid carbide burrs.
they get past the hard material and are more resistant to chipping and breaking.
 
440-c said:
if I anneal and get the holes drilled do I need to normalize the steel a couple of times to be ready for hardening?
Click to expand...

No, if it is only work hardened, just anneal it, drill the holes, and proceed to hardening .
 
My go-to on hardened steel (I used to forge a lot of O1, and the air hardening would bite me on the butt sometimes) is inexpensive glass/ceramic bits from Home Depot or Lowes. Five bucks or so and they cut hardened steel like butter.
 
Stacy E. Apelt - Bladesmith said:
No, if it is only work hardened, just anneal it, drill the holes, and proceed to hardening .
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Stacy .............my friend , we are in 21 century , we don t anneal steel just because some hole work hardened ......... :) I don t anymore even drill holes in tang for pins before HT .................:D T c-a-r-b-i-d-e will drill in hardest steel on Mars like in wood :p
 
If you already cut and milled it without a problem, I'd just re-sharpen whatever drill bit you were using and try again. Use some cutting oil and give it some good pressure.
 
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