Anyone tried drilling 440C?

joe90

joe90

Joined
Aug 17, 2001
Messages
346
What drill's did you find worked best? Carbide? Cobalt?

This is on 440C that has already been heat treated - production blade.

Thanks.

Joe
 
post heat treat :confused: now that i have not tried my bet is cobalt but its not going to be fun lots of cutting fluid and time dont want to shatter the bit
let us know how it turnes out
 
If it has already been heat treated cobalt bits won't help ya out much. You will need to get some carbide bits. Go slow and be careful.

Sean
 
Carbide bits are a must for already hardened steel. From what I understand, carbide bits are best run at faster speeds.

Bill
 
Howdy There...!
I work with 440c all the time, course it is annealed so I can do anything I want to it. I have work production blade of 440c and they are tricky to do, I suggest that you use a carbide bit , lots of cutting oil and if required anneal the spot where you want your hole to be drilled. I have had to take a torch and anneal the spot before drilling to help soften the steel a little. Good luck ...!

Later "Possum"
 
I agree with everything above, but its more like spot temper than anneal :)
440C is air hardening, so if you heat the spot up past critical it could actually come out harder :eek: (unless you can cool it down slow enough, but thats more chance of heat creeping out and ruining the temper of the entire knife) You'd do best to try and draw that spot back as much as possible without affecting the temper on the rest of the blade at the same time. Repeatedly heat the spot to a a dark blue color and then quench. If color darker than a very light yellow, ever creeps out to the blade, quench it.

To be honest though, I think your better off just going the carbide route, which you would have to do anyway, and not trying to heat the blade.
 
I recommend that you properly clamp the blade before drilling. I have a friend that was redrilling some tang holes, the knife was not clamped. This improvised cusine-art managed to cause about 38 stitches. Personally I'm at 24 stitches, two incidents of improper clamping with hard to drill situations. Carbide bits are expensive. I recommend tuning your proceedure to a high level using carbide; it saves on breakage and personal damage...Take Care...Ed
 
How big of a hole are you drilling? If it's larger than 1/4" try masonry bits for your pilot hole (you will want a pilot hole). Then use Hi-Rocs or carbide spade bits to get a clean hole at the diameter you want. I found that slow speed, moderate pressure, and plenty of Cool Tool II works well. I sharpen the bit just before breakthrough because sharpness is critical then. Be very careful from when the bit breaks through until you finish the hole; move from light to very light pressure because that's when the bit is most likely to chip. I've drilled 1/2" holes in hardened ATS-34 this way.

Do your experimenting with masonry bits. They're cheap, like $2 or $3 each so you won't feel too bad when they chip out. Oh yeah, don't even try this without a drill press.
 
Hey guys,

Thanks very much for the advice and comments. :D

I basically took this production blade to a friend of mine who works in a toolshop. He will be clamping it and using a proper drilling press. He has to purchase a 3.9mm carbide (3 flute?) drill for this one - which I said I would pay for, since it's at my request.

Hopefully we'll see what happens on Monday.

The blade already has a countersunk hole in it, where the originally thumstud goes. I'm basically wanting to "enlarge" the hole slightly to accomodate a newer dual thumstud that I have managed to aquire.

Do you think this will complicate, or simplify the process?

My friend told me that a carbide drill would probably do it. He recons that carbide drilling, if not done properly are likely to break the drill when it finally pierces the steel on the other side.

I hope this works. I really like the blade (and knife).

Thanks again for all the input - much appreciated.

Joe
 
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