Thread: Need advice on drill bits

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I am looking for a new drill bit set. I would like to buy one that is a complete set with numbers, letters and fractions. I have always had the store bought bits, like Sears, and they are horrible. I would like to get a really good set that will last more than a few holes. What brand name would you guys suggest for a very good general purpose drill bit set for a hand drill and occasional use in a small drill press?

look at use-enco.com they have a lot of stuff

I bought a set of the RIGID cobalt 30 dollars for a set 1/16"-3/8". I have always spent money on the rugular bit sets that don't last.I have been using these for a month or two ,I like them.They cut quick and don't get ruined after the first hole.Good drill bits cost more,but last longer.

The guys are right about Cobalt bits.

5% Cobalt will do the job.
There is a 10% Cobalt out there, but far as I know it's for lathe cutting bits.

The Cobalts retain their edge longer than regular HSS (High Speed Steel).

Stay away from the Chinese carbon drill sets.

The 115 piece set that Denny W shows is the hot setup.
Every once in a while you'll find American made HSS in a 115 pc set and it's not too expensive.
Under $50. in most cases.

If you're trying to stretch your money, buy a set of 5% Cobalt's to 1/2" by 64th's.
Then a set of number and letter drills in HSS.

Usually the number and letter drills are used for tap holes and don't get used too much so a lesser quality tool will do the trick here.
You do want the fractional sizes in a good quality.

If things get tough, get a Carbide drill bit.
Buy them by each size as you need them.
Most times these will have to be mail ordered.

Biggest thing that makes drills last is proper cutting speed and proper cutting oil.

Drilling a pilot hole helps as well.
Just don't make the pilot hole so large that the big drill is cutting on extreme outer edge of the bit.
There's a lot of pressure there and if you have to do it take it slow and easy and use a sufficient quantity of cutting oil to carry the heat away.

Pilot holes improve accuracy to a considerable degree as well.

C9 is giving good advice. Drill bits have a finite life that is affected by the material being drilled and how you use the bit. Unless you know how to sharpen a bit or have a GOOD sharpener, bits will dull with use....usually fairly quickly.

You can buy bits at MSC ( www.mscdirect.com ). They sell individual bits of all kinds. You want what is called "jobber" length bits for normal use.

Also, MYTOOLSTORE in Vegas sells the DeWalt pilot point bits:
http://www.mytoolstore.com/dewalt/dew02-09.html
These bits have a small tip to get the bit started. They are great for sheet metal use or for use on curved surfaces. We usually buy the bulk pack.

Instead of buying several drill indexes that have 110 bits (of which 84 you will never use) consider building a custom set tailored to your use. For instance, if you do a lot of 1/4-28 tapped holes, buy the tap drill size (No. 3) and the clearance drill size (f). You can make a holder from wood. This way, you buy two sizes for each tapped hole size that you typically use. Also, you can buy the clearance only for stuff like 1/2" bolts. You will want to buy multiple bits for your commonly used sizes.

Our guys make a wooden block (from a section of 2x4) that holds
the tap drill, the clearance drill, and the tap for each size in a row. Using a Sharpie, you label the row and VIOLA!, you have a handy holder.

Dont be tempted to by the Awful Freight stuff. Buy quality drills and they will pay for themselves.

mike in tucson

I stay away from coated drill bits, TiN being the most common. I feel most manufacturers use it to make up for a poor base metal on the rest of the bit. I agree about the Cobalt, but HSS with lube will do the job for most any metal. I've punched 30+ holes in thin 316 stainless steel using a hand sharpened HSS bit and it barely slowed down. There are 2 brands I stand by, but there are plenty of others who are acceptable. I believe Triumph Twist Drill Company and Greenfield Tap and Die are miles ahead of the competition. As for split point vs. standard, self centering isn't an issue because you should center punch your holes anyways. If you are going to be using a hand drill, the split point bits require less pressure which is a huge plus. If you own a drill press, the ease of sharpening of the standard point will be of more benefit.

HSS bits and a Drill Doctor sharpener

Even good bits won't hold up with poor use. I've drilled more holes than I care to count and yelled at even more guys ruining my bits. Just because a bit is called HSS or high speed steel doesn't meam it'll last long at that speed. BIG TIP ---- Drill SLOWLY! If your drill isn't variable speed then squeeze and release the trigger continuously. Speed creates friction which creates heat which kills the temper which dulls the bit. Use cutting oil liberally. I've made some by cutting regular motor oil with some paint thinner in a pinch. Like any other tool, take care of it and it'll take care of you. Buy good carbide if you can but HSS used correctly will work well for a long time if used right.

Steve

I'm with Robot on the Dewalt piloted drill bits.
Absolutely great with sheet metal.

I bought a set of these when I already had the shop packed up for moving.
They were terrific on drilling the sheet metal legs of my 16' long workbench so I could bolt some long angle steel to the legs for reinforcing and skidding.
Had to load the darned thing by myself - wasn't too bad using the boat trailer winch on a stand inside my enclosed car trailer to drag it on board.

The bits look like they would be tough to sharpen so they're dedicated to sheet metal use only nowadays.

Thanks for all the input. I do notmind spending good money for a good set. Is Triumph Twist and Greenfield the only ones you guys would suggest? I have borrowed a friends Precision Twist bits and they seem pretty good, but they are HSS. I would not mind paying $100 - $200 for a complete set of bits. Which name brand would you guys suggest now that I am ready to buy cobalt.

Here is a complete cobalt set made by Chicago Latrobe for $520: http://www.grainger.com/Grainger/wwg...758229&ccitem=

That's a little pricey. Grainger sells 3 brands, I believe Chicago Latrobe and CLE-Line are both American made, but Westward is not. I cannot get onto McMasterCarr's online catalog at the moment, but I believe they carry Greenfield bits.

HSS standard point is around $250 http://www.grainger.com/Grainger/wwg...618726&ccitem=
HSS split point sets are $330
http://www.grainger.com/Grainger/wwg...752474&ccitem=

OK OK OK I had no idea that cobalt bits were in the $500 range. Maybe the HSS would be good enough.

Well, there has been alot of good advise on this thread. I agree with all of it, to a point. I am with Randy. You can very easily spend alot of money on drill indexes, and buy expensive ones that will dull after a few holes. You can also get cheap indexes that will last a long time. I am in the military, and getting them to spring for anything that costs a decent amount is hard to do, value is always the way for them, so I get alot of the cheap "Stock System" made in Tiawan crap, from the lowest bidder. They don't cut more than two holes before dulling up. I combatted that by purchacing a Drill DR. for shop. You have all seen them I am sure, and sears sells them. For the price of one drill index, I got this sharpener, and I have only had to buy bits when another department borrows my drill index and breaks a bit off or something. The Drill DR. will take the worst looking, dulled up P.O.S. bit and make it like brand new sharp in maybe 60 seconds, once you know how to sharpen bits with it. It comes with a instruction video and book, and it is easy to use. I am not trying to sell the thing, just share a possitive experience, that has saved my department alot of money from buying numerous cheap drill indexes, and I can keep the ones we got sharp as the day we bought them.

JMO

I agree with 460_fan, the drill doctor is a pretty good tool for sharpening cheap bits. Have used it and am very happy with it. The only thing I don't like about it is it won't sharpen the smaller bits, don't remember the smallest size though, might be 3/16 and smaller.

I am in charge of a Lab that has machines from bench top lathes and mills to extremely large jig bores and lathes that will swing over 86" to CNC mills.

We are a prototype house. We use high speed drill bits by and large. For drilling Titanium or Inconel we might go to high quality Cobalt or even Carbide. This is rare indeed though. As others have mentioned your technique etc will play large in drilled hole quality and bit wear.

If you just drill a lot all the time buy a good quality HSS drill bit set from a good tool crib; not Harbor Freight for example. With the Drill Dr they will last a few lifetimes. Otherwise a cheapy HSS set from HF will suite you quite well; it has me!

Best Regards, Kitz