i cant make a hole

docdredd

docdredd

Joined
May 25, 2006
Messages
587
Sorry if this has been asked befor but using the search function is a lot like taking a barbwire enema:( i recently bought a delta bench drill (be kind im on a budegt) to drill through L6 for the pin holes. my question is are there drill bits that will cut hardend steel. i would prefer leaving the blades at there natural temper as im only making thin kitchen blades. when ive used my standerd bits and cutting fluid all i get is noise and excess heat hell i even melted a bit the other day when i was pissed off by bearing down on the handle (bad form i know) any advice from whoary heads would be appreciated! thanks in advance

doc silas
 
There are also solid carbide bits, but they are pretty expensive and kind of brittle. You might try the Ti coated bits. I know that they wear very well, but I'm not sure how they would work on hardened steel.

I have used solid carbide drill bits to remove broken taps, so drilling hardened L6 should not be a problem.
 
Depending on how hard the steel is, you might get away with cobalt, but you won't drill many holes with them before they get dull. You will also have to run the drill really slow and use a lot of fluid.
If you really want to make a habit of drilling hardened steel though you need to invest in some carbide drill bits. You could probably even get by with masonry bits if you're only doing holes for handle pins. You have to use light pressure and run them at high speed, but they will do the job. And of course, where safety glasses because they tend to come apart once in awhile.
I wouldn't bother with Ti coated bits. The titanium nitride is just a thin coating that makes the face of the bit extra hard. It doesn't really make that much of a difference, and once its worn away they're just like any other drill bit. Actually in most cases they use cheap steel to make the bits, so they're actually alot worse then other drill bits and not even worth sharpening. I'd much rather have a set of decent high speed steel bits any day.
 
Use carbide bits, or anneal the tang. Cobalt bits will not last. I would try to anneal the tang before buying carbide bits.
 
If you use carbide bits, be sure you put another piece of steel under the blade you are drilling. Carbide will shatter when you break through the hardened steel if you don't back your work up.
 
First off, why are you drilling after heat treat? Or are you assuming that the steel is hardened because it's eating your drill bits? Assuming the steel is as you received it, it's probably annealed, which should be easily drillable with Costco or better grade bits, assuming the other things are setup right like RPM. It sounds like you're possibly spinning the drill bit too fast to drill tool steel, even in an annealed state, or possibly you're trying to drill too big a hole with no pilot hole.

Give us more details about your setup.
 
J. MacDonald said:
First off, why are you drilling after heat treat? Or are you assuming that the steel is hardened because it's eating your drill bits? Assuming the steel is as you received it, it's probably annealed, which should be easily drillable with Costco or better grade bits, assuming the other things are setup right like RPM. It sounds like you're possibly spinning the drill bit too fast to drill tool steel, even in an annealed state, or possibly you're trying to drill too big a hole with no pilot hole.

Give us more details about your setup.
Click to expand...

Sorry i guess i should have been more specific im actualy using old saw blades they are just a tad shy of 1/8 inch. thank you all for the advice it is wonderful to be able to draw on such a well of knowledge. saves a lot of wasted time on screw ups.
 
Carbide bits, while just a tad more expensive than cobalt bits, are not really that expensive. Use lots of oil with them and always, always, always (did I say always) use them with a drill press. Also, if they break, they tend to break just before making it thru the opposite side. Use a scrap piece of steel underneath the piece you are drilling thru to help prevent this from happening.

You can get PC type carbide bits from WholesaleTools or MSCDirect for about 2 or 3 bucks each. I use the number size bits, just oversize for pin holes in tangs.

(One other thing, for 1/4" holes, I use a 6.4mm metric bit. They are .252 inches. A size F is .257 inches. Seven-thousandths is quite a bit of slop. Unless you use a precision reamer, a 1/4" pin will not fit in a hole drilled with a 1/4" bit.)

Craig
 
I haven't tried to drill hardened steel (as far as I know), but I've had to adjust the game plan after wrecking some bits on steel I thought was annealed. Before splashing out for the carbide bits, get a cobalt or ti-coated one from Home Cheapo, and slap that sucker in the chuck. Move the belt down to the lowest RPM, and drill with moderate pressure...give the bit a chance to bite. Spritz it with WD-40 or something similar every once in awhile, and take your time. If you see smoke, you're pressing too hard. If that doesn't work, then you may need to pull the trigger on a carbide tool, or anneal the metal.

Good luck,

psr
 
thanks guys i took your advice and bought some carbide bits. between them and wd40 im having much better results thanks alot.

doc silas
 
You can try Rodman and Company for drill bits. I was at a mining equipment show and I work for a bearing company (Timken). They came to our booth and asked for a bearing that they could demonstrate their drill bits on. I gave them a bearing and when I went over to their booth later in the day, I watched them drill into our bearing with absolutely no lubricant! Our bearings are 58 to 64 Rc, so that was pretty impressive. I then watched him drill into some Nicholson files, which were at about 70 Rc. I bought a set of drill bits right then and there. They work well, but I do recommend using lubricant with them. When he was drilling through the file, the end of the drill bit was glowing red, and yet it continued to cut.

It's been a great investment for me!

Here is the link to their website.

http://www.rodmanandcoinc.com/homepage.html

Good luck!

Scott (Ickie) Ickes
 
Save yourself a lot of frustration and buy some carbide dagger drill, check out the link below If you are serious about knife making, you really need get some carbide tooling. They don't even know the metal is hard. Carbide is brittle so be sure to clamp all work securely and no free hand cutting. most small work with hard steels I cut dry at about 500 rpm and adjust the feed rate for the smoothest cut. If the cuts are to light with hard metals the tool bits will actually run hotter. Practice makes perfect. The reason I cut dry is so I can ses work in progress better, other wise use a coolant & much higher RPM. Carbide Tool bits will last a very long time if you do not run them to hot and be sure you have ridged mounting

Leon Pugh
 
once again thank all of you for your input. i have found over my not so long life that you make fewer mistakes and bleed less when you are wise enough to ask the right people the right questions. as for not hand holding the stock i lernt that one the hard way. and if you have never given yourself stiches at 2am your not missing out on much. thank god for lidocain
thanks all
doc silas
 
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