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drill bit recommendations

mark thomas

Titanium
Joined
Dec 15, 2004
Location
SF Bay Area
I'm going to get a new set of standard fractional drills. Just regular jobber drills for routine drilling (mostly mild steel, but occasionally aluminum, alloy steel, etc.) But what to buy? There is such a wide price range. Looking at Enco and McMaster, the price for 1-16 to 1/2 by 64ths sets ranges from $30 to $400 dollars. More than a factor of 10 price range! I'm a hobbyist and don't need production-shop grade stuff, but I have very low patience with real low-end stuff.

The major differences seem to be:

- HSS vs. Cobalt
- 118 vs. 135 split point
- Coated (TiN or TiCN) vs. not (black oxide or bright)
- Import vs. USA (though often not stated)
- "heavy duty" vs not

Not all combinations are available of course. But at one end for $30-50 you get Enco, black oxide, 118 degree. At ~$400 you get "heavy duty" cobalt, TiN, 135 split point, American-made.

Typically under these kind of circumstances I lean towards the middle, which in this case is "Heavy Duty HSS", TiN, 135 split point (origin unstated) from McMaster for ~$200.

Any recommendations much appreciated.
 
The cheaper drills I've seen were ground very poorly, were bent, and such... problems that made them practly useless.

I bought a set of 115 drills from Doall. I guess they're somewhere in the middle of the price range. Black oxide, very smooth grind and sharp, 118 point. I'm very happy with it. For replacements or larger drills, I get PTD's.
 
I've had pretty good luck with those inexpensive TIN coated sets that you see "on special" in the Travers Tool or KBC sales flyers once in a while. Its a practical impossibility to know what quality set you'd be buying at any given moment, I suppose.
 
I don't even use a drill index, all my drills are in drawers, put in order by size. I buy all the way up to TiN coated
carbide depending on the application. If I were
to buy a drill index collection I would go with
the middle of the road $200 set, some of those
cheap drills aren't even fit to drill wood. I
have actually seen the clearances ground the
wrong way. As far as 118 vs 135 degrees on simple
thing to note 135's drill easier but don't find
center as well, 118's center easier but drill
with more pressure. Get the 118's if you won't
be countersinking most of your holes first.
 
I suggest you look at the mid-priced twist drill sets if you're going to use them on a regular basis on machine tools. I bought a 115 pc set of PTD (Precision Twist Drill) for $105 a couple years ago. They've worked well for me.

There's nothing wrong with good import drills but it's hard to distinguish the good ones from the duds. I have a $38 115 pc set of Enco import drills that I use for rough work that have withstood abuse quite well but the shanks are soft and easily damaged.

As for cobalt drills they're too expensive unless you plan to use them for drilling stainless, alloy steel or other tough materials.

Coated drills are pretty. For some jobs they can't be beat but they have little application in the home shop. They don't hurt but their coatings (and greater cost) offer little quantifiable benefit to the occasional user. As soon as you sharpen a coated drill you loose the coating where you need it most - on the rubbing edge of the clearance.

Point angle (118 degrees Vs 135) makes little difference until your drilling cinditions require one or the other. Buy a 118 set for general use. If you need a 135 degree drill for a specific job either buy one or regrind a 118 degree drill so suit.

Split point drills penetrate readily and are very productive but then again you sooner or later have to sharpen them. Same with the pilot point drills. Once these superb factory penetration features are sharpened away the drill thay came on is like any other drill.

Black oxide or bright? How important is color scheme to your tool box? I've used both and the preference seems to boil down to color scheme. Black oxide tends to shed a built up edge better.

So let two criteria sharpen your focus: pick a kind of drill that's readily hand sharpenable and of a type that's not excessive to your requirements. This takes you to a plain moly HSS 118 degree set you use for general drilling. Anything beyond represents an "overbuy" and thus a waste of purchasing power.

The most important investment a home shop drill can make is learning how to efficiently free hand sharpen twist drills. I can strongly reccommend the Drill Doctor for drills within its capacity but if you own a lathe or a mill larger drills soon make their appearance and you will have to sharpen them.

I wrote an article on twist drill lore in the May/June Home Shop Machinist. It's still on the racks in Barnes & Noble and other major book sellers. There's much in it about twist drills I couldn't discuss here in this thread.
 
It's hard to add to a sage's post but supposing you do go with the 118 deg points, just buy a 12 pack of say 1/8" drill bits.

I keep packs of 1/8" near each machine. They drill pilot holes and I consider them expendable.

So, my money is on HSS, 118 deg, black oxide, USA with a 12 pack of 1/8" bits.

If you really want to be blown away with drill bit selection, open MSC's big book. You can choose by manufacturer, Triumph, Precision Twist Drill, Chicago Latrobe, Cleveland Twist Drill are a couple of the top manufacturers IMHO.

-Matt
 
Cobalt's aren't always that expensive guys.

Knifemakers use primarily cobalt drills for drilling through titanium.
My last drill bit set was a Chicago Latrobe set from MSC. Sizes 1-60 packed inside a nice drill index for only $120.
I prefer screw machine drills when possible, for thier rigid characteristics. Of course, jobbers may be needed at times.

I have been totally satisfied with these drills and can't see myself needing anymore for a long time with regular home shop use.
They drill through mild steel great...
 
This is one place that would fit in to my "what do you miss most" thread. At my first job in the machine shop, my manager told me to go to the hardware store and buy a drill index for numbers and fractional (they didn't sell letters). He said to get that and then go to the storeroom and fill it. Mine to keep.

Since then, previous employers have refilled broken, and just now I am starting to have to refill on my own. I have been buying 118 HSS Bright USA, and they work fine. I think I'll try Forest's suggestion on the black oxide though.

I'd stay away from anything that is coated...it looks pretty, but doesn't do you much good.

My next goal is a screw machine length index in both numbers and fractional. It works much better on the Van Norman going from spot to drill bit with no quill


-Jacob
 
Mr. Addy, your articles are first rate. Thanks. Your lessons on how to sharpen drill bits, especially web thinning, are valuable. My ability to sharpen bits allows me to use nearly any bit that comes my way, whether originally cheap or expensive. Did you guys know twist drills lose diameter as you move up from the tip? Forrest taught me that!
 
I like the Hertel brand (US made) 115 piece set in bright finish sold by J&L. They have it on sale about 10 times a year for $79.95.
 
When buying drill bits, the main thing to remember is the price --YOU ONLY GET WHAT YOU PAY FOR. Go buy a GOOD set of drills and you will be happy with them, buy the ****ty cheap ones and there all yours.
 
A bit off thread: I have used quite a few very low priced 1/2" shank drills (9/16-1")in my magnetic drill, doing literally hundreds of holes in A-36 structurals and plate. Made in China, black oxide finish, 8 to a box, $25. Real junk, right? Well, they have to be resharpened initially (which is mandatory) and then no more frequently than any other bit. The key to making a bit long lasting is to resharpen frequently. I've been pleasantly surprised and have saved much money from this nothing ventured, nothing learned experiment.
 
Years ago I bought a little booklet from Lindsay publications called the "Handbook for Drillers". It's a reprint of a booklet put out in 1925 by the Cleveland Twist Drill Co. It's only about 50 pages, but it has loads of info on using, sharpening and maintaining drill bits, practically all of it still relevant today. Not sure if it's still in print, but I think I only paid about 3 bucks for mine, and I still refer to it sometimes.
I have a set of bright finished Hertel's at home from J&L also. They are good qualilty, and not that expensive.
 
I am somewhat hesitant to add anything after Forrest has weighed in on this subject, but..... I read in another thread that for drilling aluminum, a bright finish drill bit was better than a black oxide coated one? Something about less buildup on the flute edges??

I bought one of those imported TIN coated 115 piece drill sets about ten years ago. Frankly the smaller drills are not very straight, but they have provided pretty good service. Since I don't use all of the sizes, when I need to buy a replacement I get black oxide USA made in a quantity that will last a while.

I picked up an old metal Cleveland Twist Drill, combination drill and reamer storage cabinet. It needs a little work, some paint and some new decals and then most everything will get stored in that.
 
At the recent Rutland Tool sale, I stopped by the Greenfield booth. They had the complete sets of black jobbers in the index for $100 or so. The bright finish index was $520.

I have a mixture of drills here. In the past guys would pull a new drill out of stock rather than touch up a slightly worn drill. It is amazing the number of used 3/8" drills in the boxes and drawers around here.

Les
 
Not much I can add to Forrest Addy's comments except to say Ive done about the same and it has worked for me. I bought one of those ENCO 115 piece import sets. A couple of the number size drills were bent but easily replaced for pennies. The rest have done very well. I sharpen by hand but a Drill Doctor appears to be a good thing. Anyway good HSS drills are fine in my opinion IF you know how to sharpen. If you don't the expensive drills won't do you much good for long. I also have a good set of machine screw drills. These are for starting holes where placement is critical. High quality expensive tooling is wonderful but there is no substitute for skill and patience. With the right mix of skill and tools you can do a lot on a small budget.
 
Thanks for the tips. I've changed my mind and I am going to go with a known-quality set of HSS bright 118 degree.

Upon reflection I realize that most of my experience with drills in the last few years has been at the extremes: crappy cheap stuff, or expensive cobalt, TiN stuff, simply because that is what the local stores sell. I know every time I drill a hole I think to myself, "gee, how come drilling seems so different than 10 years ago, when cheap bits worked well?". I think the answer is that back then, cheap bits were basic USA quality stuff. Nowadays, none of the local places (Ace Hardware, Home Depot, etc) stock basic quality stuff anymore -- they only stock low-end crap and high-end fancy stuff. I just need to order known stuff online and stop shopping at the local "hardware store" (I put in quotes because they don't deserve the name anymore! I am just old enough to have grown up at the tail end of real "hardware stores", where they seemingly stocked everything, nothing was wrapped in plastic, and they had staff who spoke Engligh and whose prior experience was not burger flipping)

Thanks everyone.
 
.......Yeah Mark, I just loved our old downtown hardware store. Closed after 86 years and not because of no business. The building owner wanted their space to combine with one next door for a pizza place. Sheesh! When I was a kid it had a creaky wooden floor and old guys working in it.

More recently it had a creaky linoleum floor and old guys working in it.

Btw, to be on topic about drill bits. I recently bought a 29 piece fractional set of parabolics for use in the lathe in deep drilling. Most any size above 1/4" and you can just drill right on through without peck drilling. Kewl! These were black oxide 118* split point.

Rick
 
I have three cobalt tap drills, for 1/2"NC, 5/8"NC & 3/4"NC taps. For production drilling in HRS flat stock, they are the ticket.

Not only do they allow faster SFM, they also go twice as many holes between sharpening. The speed I use produces about half amber-colored chips & half blue chips. They clearly tell you when resharpening is needed -- they produce red sparks as the drill penetrates the back side of the hot-rolled.

Mark, to answer your question, I've also had success with J&L's Hertel brand (made in USA) sets. Their Silver & Deming set (about $100 on sale) does a great job on the bigger holes.

You may also see something here you like:

http://www.jlindustrial.com/hotdeals/invblowout.jsp

Barry Milton
 
Forrest hit it right on. I'll also second Pete913s suggestion on the Cleveland Handbook for Drillers. I have a later WWII vintage copy, but the info is the same. That book, a good Starrett drill point gage, and some degree of mechanical aptitude will assure you of successful hand sharpening. It takes some practice, but our shop had a pile of ruined bits for me to practice on. In the end, I learned to sharpen bits and we now have a bunch of useable (although somewhat shorter) bits.

A Starrett drill gage is about $40, but it is an essential tool for hand sharpening. The gage ensures the proper angle and matching lip length. I have tried to sharpen drills without the gage and have seen others try. All you have to do is put the gage on a free-hand sharpened bit and you quickly realize the eyeball just isn't well suited to this job.

I also have a Drill Doctor, the little $80 one. It was given to me and at first I found it to be pretty useless. I was trying to sharpen some badly damaged and/or broken bits. The Drill Dr will not re-point a bit very well. If you just want to touch up a slightly dull bit, the Dr is lightning fast and does a very nice job. Badly worn, burnt up, or broken bits must first be repointed by hand.

I don't waste time sharpening bits under 3/32 with the Drill Dr or under about 3/16 by hand. The local surplus tool shop down here sells bits for nearly nothing. It's just not worth the time.
 








 
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