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Best drill bits?????
Hi all,
I've been hard at my 30 Plymouth for about a year now. In this time I've bought 3 sets of drill bits. DeWalt titanium, Hitachi and Craftsman titanium. These were the sets off the self at Lowes and Sears 1/16-1/2. The sets were $30-$50 each. I break them, bend them and if they don't bend or break they're only good for one shot. Today I was using a brand new 7/32 bit to drill out a broken 5/16 bolt and the darn thing bent right before my eyes and the another one was only good to drill out one rusty 77 year old rear fender bolt. What gives? Are drill bits all from China, Korea, Japan, India? Apparently they must only be coated with titanium? A buddy of mine said to buy cobalt steel bits and they will last and can be resharpened to like new condition because their cobalt through and through...not coated. Is this true? I found a set of cobalt at Sears tonight for a whopping $100 bill. Are they junk? If there is something better please let me know? Thanks |
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I like the cobalt drill bits...they are high priced but they are worth it.
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The Triumph or Cleavland drill bits from the link below are really good and priced right but I am somewhat surprised you are having trouble with the Craftsman bits. I am no fan of Craftsman tools however the drill bits they sell have been as good as anything I have ever used with the exception of the Cobalt bits from $nap-on, which are REALLY good but pricey. Cobalt bits will outlast most anything else but will break fairly easy so they are better suited to machine drilling although they do work ok with a hand held drill if you are careful, JMO on that one though. There is no excuse for a drill bit bending and if that happens to one that is supposed to be a good brand name then it most likely is counterfeit which happens sometimes with a lot of products. You are right about the Titanium coating on those bits as it is just a coating that will help a bit run cooler and remain sharp longer however if the bit it is on is junk to begin with it will not help much if any at all. When I ran my shop we used a heck of a lot of bits and the performance for the money was hard to beat for either the Triumph or Cleavland bits from Enco, even their cheapo bits work darn good for the price although they are not the quality of the good ones.
www.use-enco.com Look at where the bits are made before buying and never buy one form China or Taiwan! |
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That's what I meant when I said the Cobalt worked better for machine drilling instead of in a hand drill. They work great in a hand drill, better than anything else, but it is easy to chip or break one with a hand drill. Another cheap trick to try when drilling something really hard and maybe having to start on a jagged surface is to use a masonry bit which will drill through most any material and they are very cheap. A masonry bit will cut a rather ragged hole and is not all that accurate as far as hole sizing but in a pinch it can do things a regular bit could never dream of, for instance I have actually drilled out broken taps with them.
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I use Vermont American mostly. if they break, Vermont American has an unconditional lifetime warranty as long as you keep the pkg.. my local hardware has no problem exchanging, even if they didn't sell the bit.. they cut decent too
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Thanks for the info. I will admit this car project has been rough on me and my tools. Maybe I need to ease up a little using the hand drill. I found some cobalt drill sets at Grainger and Sears but before I buy I'm going to make sure they're USA made.
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They haven't been mentioned yet but I have used my Hilti set A LOT. I don't know if anyone else here can vouch for them, but I have had nothing but good luck with Hilti drill bits.
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I have had great luck with the Triumph bits. I have a set with the three flats on the shank that work the best with keyless chucks.
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I actually use concrete percusion bits to drill very hard steel, but you have to drill at a very high speed. my boss has a special set of high speed bits for hard steel, they have a carbide tip on them and work very well but are super expensive. one day I wanted to use one of them and he basically implied for me to buy my own set. so after looking at them and the carbide tip I figure I would try a concrete bit. I very lightly dressed the tip on a green grinder wheel we have for carbide and tried it.. they drill just as well as the high dollar bits and I use them all the time and they last
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Mike, That's what I was talking about when I mentioned the Masonry bits and they do work better than most people think. I would not want to drill a precision hole with one but they work pretty darn good for some uses. A few years back there was a mod being done to Mack trucks to correct a design flaw that was cracking the cab cowl and this involved drilling eight 5/8" holes trough the frame. The frame was either two or three layers of frame steel (and we are talking Mack truck frame) depending on model and hole location and these had to be drilled by hand because of space limitations. Because of the difficulty of drilling this stuff in this manner we used only the good bits mostly TiN coated or Carbide but we broke or otherwise ruined a lot of them. When we ran out of bits late one evening the only store still open was the local Ace hardware who did not have a good 5/8" bit on hand so I sent a guy down to buy a couple of 5/8" Masonry bits, we thought maybe they would do in a pinch and would be worth a try but we were in for a surprise! Not only did they drill those holes just fine they drilled far more holes per bit plus they drilled faster which was a big plus for the guys holding the drill on this very tiresome job, they also cost $4.19 each as compared to $19 to $25 each for the other bits. I am not saying we should all just fill up our bit boxes with Masonry bits but sometimes they will work and work very well.
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drill bits
I can't speak for everyone, but from my experience, when a bit breaks, its pushed on to hard or sideways, or it hangs up and breaks. I sharpen my own bit with a 750x750 drill dr. For drilling hard material I use less angle on the point, which give you more surface contact but take a smaller bite from the metal. I also cut the tip of the bit's cutting edge. Its hard to explain this. I grind the tip of the bit on the cutting edge long ways removing part of the cutting edge so its flat, this way it makes the tip stronger and not as sharp. I'd try showing you what I mean, but I don't know how to send in pictures as other have done. I got a dig. camera, but I never taken the time to learn how its done. If you're interested I got the drill dr. on line from ace hardware through e-bay for about 140.00 tax,tag, and title delivered. It'll sharpen every kind of bit I've come across 3/32 to 3/4 even mason. They even have a chuck for sharpening left hand bits. (about 30.00 extra) Hope this helps.
P.S. If you start drilling and you don't see metal shaving, you might want to stop, because you're not drilling, you're only making the bit get hot and burning up the tip, and when you resharpen it, you going to have to take more off it to remove the metal which lost it temp when it go to hot. oil or tap magic helps to. |
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I like the cobalts best.
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Quote:
As far as new drill bits, I try to buy the Hitachi or DeWalt titanium coated locally(Lowes) or the regulars from McMaster-Carr. You can buy 3-4 good, usually USA made, for the price of one junk Chinese made bit from Home Depot. If I needed them to really last for business, I'd spend the extra for the cobalt steel version though (also from McM-C) Dave |
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