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gincoza

gincoza

Joined
Jan 22, 2010
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69
am in need of some good carbide dril bits, where can I get them?,,is there one certain kind I need... am using them to drill holes in tangs etc,,
 
May I ask why you need carbide? Are you drilling through a blade in the hardened state?
 
Plus what are you going to use them in. You must use either a good drill press and have the work clamped or use them in a mill. They are extremely brittle and will snap in a heart beat if not in a rigid setup. Do a search here for carbide drills and the size you want in decimal
http://www1.mscdirect.com
 
carbide bits are a must for drilling through hardened steel, but they are also excellent for drilling through any non annealed stock. i've got a bunch of carbon steel bits i've had to heat treat several times now (admittedly due somewhat to misuse).

the carbide bits are a godsend for repeatedly drilling pin holes.

The Dewalt carbide boring twist bits i have used are great. They are the ones with their pilot point and the gold tip (though they claim to be WC, i think they use TiC as well, which would explain the color). I don't have very much experience with other brands.

always lubricate and the bits will last a long time. fail to do so and they'll be quickly relegated to use on wood.
 
canid said:
carbide bits are a must for drilling through hardened steel, but they are also excellent for drilling through any non annealed stock. i've got a bunch of carbon steel bits i've had to heat treat several times now (admittedly due somewhat to misuse).

the carbide bits are a godsend for repeatedly drilling pin holes.

The Dewalt carbide boring twist bits i have used are great. They are the ones with their pilot point and the gold tip (though they claim to be WC, i think they use TiC as well, which would explain the color). I don't have very much experience with other brands.

always lubricate and the bits will last a long time. fail to do so and they'll be quickly relegated to use on wood.
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That's funny. Wood is one of the few materials where I would use a carbide drill bit. A carbide circuit board bit to be specific. Wood and plastic, and other abrasive material that don't require a particularly robust edge do well with carbide drills. I would never use carbide to drill any knife steel unless it was hardened and I was using a heavy duty straight flute drill and that was my only option. It has never come up.

You're re heat treating your drill bits? That's incredible. What kind of steel are they? Can you describe your process?

So, you get very good life if you lubricate, but the carbide bits you use fail quickly if used dry. That is an interesting observation to me, I haven't really run across that, but I probably don't have as much experience as you do. How fast are you turning your bits? What kind of setup are you using for this?

I've always had really good luck using regular old USA made HSS and cobalt HSS in unhardened knife steels, drilling hundreds of holes with one bit with no problems. I guess I should feel fortunate I've been getting so lucky. Perhaps it is the little bit of corrosion inhibiting oil that is already on the steel that is doing it. Any thoughts on that?
 
i've overheated the bits many times and watched them dull imediately thereafter. when sharpening them on the disk hasn't helped i've tried heat treating them:

quick heat and oil quench. i have no idea what kind of steel they are. it seems to work just fine.

always lubricate and the bits will last a long time. fail to do so and they'll be quickly relegated to use on wood.
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this is just reitteration of the advice i've always been given. i'm happy to bow to greater experience.
 
i can't think of where i would use carbide bits on wood. any bit i've got laying around will do the job with a quick touch up on the cutting edges. should i be doing differently?

do you think i'm ruining the bits i have? i get that impression from your reply.
 
This forums is, in my opinion, one of the best on the web. We're largely self regulated here. There are a few unwritten rules here, one of which is, we all try our best to not give bad advice, which prevents other folks from spending their time and money on wild goose chases.

Nobody is perfect, and we all make mistakes. But your post is not just a simple error, is it full of bad advice and bad information, and in my opinion it crossed the line into bullshit laid on thick. So I called you out on it. If I hadn't, someone else probably would have. We don't need that here.

Some bad information:

"carbide bits are a must for drilling through hardened steel, but they are also excellent for drilling through any non annealed stock."
Based on something else you state later, I think you might be talking about carbide tipped masonry hammer drill bits? I'm not sure. But if you're using real carbide drill bits, I seriously doubt that you, or very many people on this forum are setup to use carbide drill bits properly in steel in order to achieve the extended life and performance compared to regular bits to justify their high costs. For most people, carbide drills will fail quickly because the cutting edge is fragile compared to a regular HSS bit. That is why they are normally only used in soft materials.

"i've got a bunch of carbon steel bits i've had to heat treat several times now (admittedly due somewhat to misuse)."
"i've overheated the bits many times and watched them dull imediately thereafter. when sharpening them on the disk hasn't helped i've tried heat treating them:
quick heat and oil quench. i have no idea what kind of steel they are. it seems to work just fine."
Practically all drill bits are a high speed steel of some sort. Even cheep Chinese bits are usually M2 HSS. I'll bet, if you look at the tang, HSS is roll stamped into it. I don't think a "quick heat and oil quench" is going to work well for HSS. M2 is generally austenitized in salt or inert atmosphere to around 2,200 deg F, which is bright yellow hot and in the neighborhood of welding heat. It is frequently quenched in molten salt. And then tempered at over a thousand deg. I doubt you're doing that. I don't know what your process would do, but I don't think anything good would come from it.

"i can't think of where i would use carbide bits on wood."
I can't think of where I'd use a masonry bit on anything but masonry or perhaps a tang I forgot to drill before hardening that needed a crude hole gnawed in it. But real carbide drill bits are used in wood all the time. It is actually one of the best applications for them.


"always lubricate and the bits will last a long time. fail to do so and they'll be quickly relegated to use on wood."
Carbide drill bits don't need to be lubricated. If run at proper speed for carbide, oil will burn, and water will check the tip due to interrupted cooling during drilling. Industry address this problem with high pressure coolant (1000 psi and higher) run through small holes in the bit. Otherwise, you use HSS, which tolerates the thermal shock. Someone using a carbide drill in steel in their home shop don't need oil. I don't think they will notice much difference in tool life. And I don't know about you, but I only use very sharp bits in wood, otherwise it is bad about tearing. But less than sharp bits work fine in steel. So you got that backwards too. Almost every statement you made was wrong (and I don't have a problem with that), yet you delivered the information as if you were an authority on the matter, giving people some really wrong ideas. I have a problem with that.

So, to sum up, I think that you don't know what you're talking about (and that is not a sin), I think you know that you don't know what you're talking about, and yet you're dolling out harmful information on our forum. We deserve better than that.
 
that's a little bit better than being a prick; so thanks.

i wouldn't give bad advice if i recognized it as such.

I think you know that you don't know what you're talking about, and yet you're dolling out harmful information on our forum. We deserve better than that.
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and we're back to being a prick.

if i'm giving bad advice tell me. if you have the time tell me where/why. these things both help me and the community.

don't speak to me like that. you're certainly free to do so, but it's not helping anybody. telling me and the public that i'm deliberately misleading people crossed a line. are you trying to educate us or insult me?

as to the remainder of your statements; i'm currently digesting what you said and researching it. it may be hard to believe while i'm being defensive, but i'd rather be correct than 'right' any day of the week.
 
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Canid,
#1 drill bit are purpose tools, each design is for a specific purpose, so choose your bit carefully. The fact that you have overheated bits tells me that your bit selection is not correct.
#2 they are diposable, if you overheat a bit then pitch it.
#3 when discussing carbide bit there are 3 broad categories; masonry bits, spiral fluted for soft materials, and straight fluted bits for drilling hardened steel.
#4 please use some cutting fluid when drilling hard materials.
#5 sharpening your own bits is great, I do that myself

gincoza,
Check out the straight flute carbide bits from MSC
They are a bit pricy, but worth every penny.

Thanks,
Del
 
canid , you said you would do the research on Nathan's statements above . Good for you , because you will find that he is correct and you have been mislead in the past . We all learn this way and I for one thank Nathan for speaking up . Don't get defensive .

I have seen advice given here on the forum regarding electrical work from people that actually believed they knew , yet that advice could have resulted in somebodies death if not called out on .
 
don't get me wrong; i thank Nathan for speaking up too. Everything but the derisive tone was well received, and everything but the statement that i was deliberately misleading the other user was appropriate.
 
Canid,

I read back through what you wrote and what I wrote and I feel I was probably a little out of line giving you hell for your posts.

You see, it is a real pet peeve of mine when people who don't know what they're talking about give advice to folks looking for information, when they know good-and-well they really haven't the foggiest idea what they're talking about. Bull shitters. And that is how you came across to me. But looking back at it, I can see I failed to give you the benefit of the doubt. That, and it isn't my place to police these forums. I apologize for being a prick.
 
Ginkoza, if you are drilling annealed steel use new quality HSS bits, put a centerpunch mark where you are planning to drill to get things started (it really helps) and use very slow speeds (150 RPM if your drillpress will handle it) and lots of oil and make sure you clamp the blade firmly so it doesn't grab the drill as it exits the backside and spin it at you. If your tang is already hardened or is improperly annealed go with the straight flute carbide bit as Delbert reccommended. They are very brittle and do not like side forces so use them in a drill press only and do not shock them and buy a couple for when they break

-Page
 
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