# Drilling Hardened Steel



## Marko Tsourkan (Aug 5, 2011)

In one Kramer's video, he drills a handle for a mosaic pin while the blade is in the handle. He uses a milling machine with an automatic downward feed. 
Got me thinking, what bits would one use to for that? Unless Bob softened a tang, the hardness would be around 59RC. Is there a bit that can tackle that hardness?

M


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## SpikeC (Aug 5, 2011)

Carbide springs to mind.


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## WillC (Aug 5, 2011)

Tungsten Carbide tipped drills do it. Or just spot temper that area before assembling.


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## Dave Martell (Aug 5, 2011)

Carbide - Del turned me onto them and it's like buttah going through 60Rc steel. If you have a mill or a good drill press you can use solid carbide bits but if you've got a sloppy press with some runout you'll be better off with carbide tipped bits because they'll bend instead of blow up in your face.


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## Marko Tsourkan (Aug 6, 2011)

So, with solid carbide bits and carbide tipped bits, can you drill through any hardness, say 60-62RC or is there a ceiling?

M


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## ajhuff (Aug 6, 2011)

The bit just has to be harder than the substrate. Carbides are 80+ hRc so you should be fine.

-AJ


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## Dave Martell (Aug 6, 2011)

Yeah they should be fine Marko. I've had a few knives with uber hard tangs that got drilled with these bits to 1/4" like it was nothing.


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## jmforge (Aug 7, 2011)

Until they explode. LOL Carbide will cut almost anything, but it is supposedly about as brittle as anything you will ever use.


Dave Martell said:


> Yeah they should be fine Marko. I've had a few knives with uber hard tangs that got drilled with these bits to 1/4" like it was nothing.


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## Rottman (Aug 7, 2011)

Drillpress should be mandatory for carbide tools. Freehanding is just likely to kill expensive stuff like this.


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## Eamon Burke (Aug 7, 2011)

******* said:


> Until they explode. LOL Carbide will cut almost anything, but it is supposedly about as brittle as anything you will ever use.


 
Same advice to prevent anything from exploding before it's time...as slow as possible, lots of lube.

:saythat:


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