Drill Bit questions.....

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As long as you have "OK" quality bits, long life is more about proper use, speed, pressure, lube, cooling, etc than brand. Any bit can be burned up by driving it too fast, or chipped by not driving it straight/steady. If your limited to hand drilling, your better off buying cheaper bits and replacing them often, if you have proper tools, heavy drill press, mill, etc then buying better grade may net longer life. Higher end bits like cobalt, carbide are more brittle, much more likely to be chipped or broken when used in a hand drill, HHS is more flexible, a better choice for most home shop applications.

Enco has some nice sets on sale;

Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies
 
Enco has some good Chinese crap. I bought a set of drill bits there about 10 years ago, and still have most of them. They were some of the sharpest bits I've ever come across right out of the box.

They had the best deals on abrasives back then too, like belts and disks. I haven't shopped there in quite a while though.


-Spike
 
It is a bit sharpener and will save your ass time after time. Not only will it save money, it saves a TON of time.
After having one for a year, bit strength is much more important, but I'm going to stick the the Dewalt bits until they're nubs. They hold an edge well and easy to sharpen.
 
Trollhole said:
I've always had very good luck with colbalt bits. They have outlasted all my other bits and I'm pretty hard on my stuff.

Milwaukee 48-89-0050 29 Piece 1/16-Inch to 1/2-Inch Cobalt Twist Drill Bit Assortment in Metal Index

A good set will run you over a hunderd easily. Stay away from any that say coated. It should be cobalt all the way through.
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I am going for the Milwaukee, I should have known that! Thanks for getting me back on track. I already own their sawzall and 18V drill. both tools have proved indestructable so far - I am going to get that set!!!

Thanks for the info.
 
Cleveland, Chicago Latrobe, Precision, and Norseman are the industrial gold standards. Dewalt, Milwaukee, Bosch, etc all outsource their bits and I've yet to find one that holds up as well as the Clevelands I buy for work. A single 1/2" jobber length cobalt plain finish bit from any of those manufacturers runs about $14, but they last forever if used properly. I deal with a lot of stainless steel at work and I cannot stand cheap drill bits.

Also, get a quality cutting fluid (not wd-40, etc) and use it liberally any time you're drilling metal. Cleanup takes a minute or two longer but you'll drill much faster and exponentially increase the life of the bit.
 
Thank you for that information, I do need some cutting oil - I have not used that before. I must have ruined more bits not using it too. I just went for a set of craftsman Colbalt I found on ebay. I hope they are decent, I drill metal maybe once or twice a month, not much -usually drilling out old screws, that kind of small stuff.
 
CDUFF7 said:
Thank you for that information, I do need some cutting oil - I have not used that before. I must have ruined more bits not using it too. I just went for a set of craftsman Colbalt I found on ebay. I hope they are decent, I drill metal maybe once or twice a month, not much -usually drilling out old screws, that kind of small stuff.
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You won't ruin bits by running them dry if you don't overheat the bit, but cutting fluid keeps the tip cooler which makes the bit last longer. It also aids chip flow. You can drill at higher speeds if the bit is lubricated. Coated bits (black oxide, TiN, TiAlN, TiCN) allow increased speeds as well but may not work on all metals (black oxide not for stainless, TiAlN not for aluminum).

I keep Tap Magic ProTap cutting/tapping fluid in the shop at work - it works well and is good for all metals. RapidTap and LPS Tapmatic are also good. Any of those three cost $10-12 a pint. Just make sure that whatever you buy is a universal fluid that is designed for aluminum and yellow metals as well as steels. Some cutting fluids will discolor aluminum and brass/bronze.

When you're drilling you want curly strings or large chips. If you're getting small slivers then either
a- your bit's dull
b- you're running too fast/hot
c- you're moving the bit around/not drilling at a consistent angle.

Also, you want 135 degree split point bits. 118 degree is designed as a universal wood/plastic/soft metal bit and will walk around on steel.

:cheers:
 
Learn to sharpen by hand on a bench grinder, and pick yourself up a few tins of prime old time bits with a little surface rust or a chipped tip from your local trash and treasure market.
I've bought piles of $20+ bits that just needed a bit of surface rust taken off them- and the odd one sharpened up- usually at less than 50c a pop.
Anything smaller than a couple of mm gets a bit tricky to sharpen by hand for me so I buy them fresh. Drill doctor would be good for the little ones- but I see it as a bit of a waste for the big ones which are really easy to sharpen well by hand.
One day I will get a drill doctor- but its far down the list.
However, if you need a hole to be and EXACT sized hole, start with a new bit, or a properly re-sharpened one. Hand sharpened tend to cut a little wider.
 
Pinion said:
Get a Drill Doctor.
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YOu like it huh?

I was just considering one. I blew three bits today. Total price will be about $20-$25 to replace them. Drill Doctor = 89.00 at Lowes. Seems like a no-brainer if it works.
 
I have a big Drill Doctor.
Works well after some practice. Although the system is a bit funky.

Have a couple sets of Cobalt drills. They tend to break easily.
 
Drill Doctor Is Awesome!

I just got a Drill Doctor yesterday. XP model. Very nice. I always thought it was a hokey thing to by but I think it is one of the best tools I have bought for myself. $89 on sale at Lowes. I sharpened a few $10 bits and tried them out. Worked like new.

In my shop I have a bucket I throw scrap metal in. I dug through it and recovered about 5 bits. a couple big ones. Sharpened those too. I am pretty sure I already payed for the thing. A great purchase.
 
for sure, if you don't have a drill doctor, try with a grinder. Can't hurt much. I'm not that good at it, but can be done with some practice. Flick o' the wrist...
 
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