Drill Bit Advice

E

ErikD

Joined
Dec 5, 2000
Messages
1,875
I have searched this forum already for adive on what the best drill bits for knife making are. From what I have read the cobalt bits are the best to get, and you only need certain sizes. While at the Home Depot today I picked up a set of Bosch titanium bits. My plan is now to buy the better cobalt bits as I need them and replace them in this set.

What I would like from those who have more experience than me is a reccomendation of a good brand. I have done some looking and see some large variation in price of cobalt drill bits. As far as I am concerned for the fews bits I will need to buy, I would rather buy the best quality I can. Any brands that set themselves out as truly better? Thanks in advance.
 
Unfortunately all I can tell you is that I wasn't happy with Dewalt's cobalt bits. The point doesn't seem to be ground at the proper angle for drilling steel, I had trouble with 3 of the 6 bits I bought drilling triangular/out of round holes.
I've had that problem with alot of different bits drilling holes in .040" 410 stainless steel that I use for liners on folders, but the dewalt bits didn't do very well on 1/8" O1 either :(
 
I think you would be perfectly happy with TIN coated, 135 degree split point drill bits. The cobalt can be kind of brittle(they seem to break easy), and unless you're drilling partially hardened steel, I don't think you need them.:eek:
 
go to the MSC website..........www.mscdirect.com and order a catalog


You can pay $.65 for some cobalt drill bits, and $2.50 for the SAME thing.......made by an expensive US company.......I do NOT buy the expensive ones.
 
As stated, unless you are drilling hardened material, or titanium, I would recommend the cheaper bits. Actually, I have found that in the long run, it is almost better to buy cheap bits, get a half-dozen good holes out of em, and then, either sharpen or toss. I bought a drill sharpener and use it for anything over 1/8". The smaller sizes I buy cheap MSC bits and toss em as soon as they go dull or chip. It is not worth the $0.80 for a new bit to have to move a hole or try and fish a broken bit out of a half-through hole because it got dull and you were trying to force it through the steel and it broke. Ask me how I know. ;)
 
Couple follow up questions:

First are drill bit stainless, or can they be tossed in a can and recycled as damascus once they're "dead"?

Second, what is the relationship between the right drill bit size and the pin diameter?

Thanks,

JD
 
All the high speed steel bits i've seen would bet were high carbon, not stainless. Though they generally have some kind of coating that may affect their usefulness as part of damascus. I'd guess for sure that any titanium or Zirconium(Craftsman) coated bits would be no good for stainless.

uh, second question, is jsut a good question. :) Lots of people have answered this before, and I ahve a chart somewhere that would probably give a good guess, but someone else could answer better. My general understanding is that you need to go to the other types of sizing(ie think it was F for 1/8" or something along those lines), that just going up 1/64" or something doesn't work too well. least, that's advice I've generally gotten
 
Originally posted by Joss
Couple follow up questions:


Second, what is the relationship between the right drill bit size and the pin diameter?

Thanks,

JD
Click to expand...

1/16" = #52
3/32" = #41 or 40
1/8" = #30
5/32" = #21 or 22
3/16" = #10
1/4" = #"F" or metric 6.4mm

These are general rules of thumb for making fixed blade knives. If you are doing high precision folders, you would want to mike all your pin material, and then chose the appropriate bit.
Rod, or pin material runs slightly oversize from it's advertized size.:eek:
 
Something to add, is that if you want really precision hole sizes, then you should use letter and number drills for the most part, drill undersized holes, then use a reamer to finish the hole to size. Drill bits wobble a little bit as they drill a hole, reamers straighten it out. I always end up just drilling the holes then sanding the pinstock a bit to match the hole, but then I don't do folders where things are much more critical.
 
I am still using the $19.00 ebay set that I bought a couple years ago. They are on ebay all the time. Just look for the 119 piece ti coated set. They have number sizes and letter sizes along with the fractional sizes. You will need a dial caliper to measure the bit and pins or bolts etc. to gain a few thousands clearance. When they wear out just replace them with HCC (high carbon steel) ones. The cobalt are better but only if you have a drill press as theses are brittle and wont take any amount of wobble. Always lubricate to prevent burning the bit and hardening the steel (work hardening)

I wouldnt bother adding them to damascus as there are better materials for that although I have often thought about honeycomb patterns possible with canninster method using allen wrenches and powder. Oops I just gave away one of my secrets.

I always use a reamer to make a precision hole for a folder pivot.
 
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