LumberJocks

How do you identify good steel from bad in tools like drill bits

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by Whiskers posted 12-14-2012 06:47 AM 1549 views 0 times favorited 18 replies Add to Favorites Watch
View Whiskers's profile

Whiskers

389 posts in 771 days


12-14-2012 06:47 AM

Hope the topic kind of explains itself, but here is the thing, I have literally 2 lifetimes of tools. Many of them are actually 2 lifetimes old, older than me. Frankly, the concept of sharpening a drill bit was not something my father would have even considered, cause he only worked with wood and let’s face it, things were made better in his day and they didn’t wear out, and if they did, they were so cheap you just replaced them. LOL, most of my hand tools are Craftsman, and we all know what people think of Craftsman tools now, but than again 1/2 are older than I am, and I’m 53, and Craftsman really meant something back than. The other half got picked up when I was in my early 20s as a set just to fill the gaps in what us kids had managed to loose for my father and Craftsman still meant something than. So I have all these drill bits, spade, brad point, you name it. Some still work quite well, others are dull as a rock. Is there a way to test the metal or tell by looking at it whether it worth trying to sharpen it, which I’ve yet to learn how to do but can, or rather it better to chuck it and buy something decent. I don’t want to waste a lot of time and resources sharpening crappy low carbon harbor freight quality junk. I know the obvious stupid answer is sharpen it and see if it holds up, but that seems a waste of resources and time to me. I’d rather identify where my tools are lacking and throw many at it than waste precious time. Also anyone know a really great place to buy quality drill bits? Especially spade bits.


18 replies so far

View Rob's profile

Rob

407 posts in 1815 days


#1 posted 12-14-2012 07:06 AM

You could try scratching materials of varying known hardnesses to find out the hardness of each drill bit. Where it lies on the hardness spectrum determines how well it holds its edge, how brittle it is, and more, which is why different types of drill bit materials are better suited for drilling different types of materials.

Another fairly simple approach that doesn’t take much time would be to get a Drill Doctor and just sharpen them. I was a bit hesitant to get one myself, but decided if each grinding wheel for the Drill Doctor costs $20 and supposedly sharpens about 200 bits before needing to be replaced, it’ll pay for itself over time—plus, it’s more convenient than having to run to the hardware store to buy a new bit (or a new set of bits) whenever I wear one out. They do now have a newer model that also sharpens spade bits, but it costs about $100, compared to $50 for the entry-level twist bit sharpener.

View gfadvm's profile (online now)

gfadvm

11479 posts in 1434 days


#2 posted 12-15-2012 03:17 AM

Rob- I have sharpened WAY more than 200 bits with my Drill Dr and it was used when I bought it off CL. It has paid for itself many times. I’d just sharpen what you’ve got as it doesn’t take great quality steel to drill most woods.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View Whiskers's profile

Whiskers

389 posts in 771 days


#3 posted 12-15-2012 03:28 AM

pulled out one of the antique 7/16 inch spade bits tonight cause I needed to drill 4 holes thru 2 2×8’s I had married together with some kreg screws for another project, and dispite the fact the bit was kind of funky looking, pitted, has whiteish corrosion on it, and some traces of rust, wonder what that white stuff is, anyway it still cut thru those 2×8s with ease. Definately a argument for cleaning and sharpening these old antique bits. I bought me a wire brush for my bench grinder couple months ago, think i’ll install it gonna go to town on them with it. Next time I go to the library I’m also going to look up about how to sharpen spade bits. Seems like it should be easy from looking at them. Drill doctor is worthy consideration, but I also have a dremel tool that might be able to do the job. Anyone ever use those for that?

View crank49's profile

crank49

3506 posts in 1715 days


#4 posted 12-15-2012 03:39 AM

For what it’s worth, some folks on LJ make their own brad point bits from regular HSS bits.
It’s a great idea because a brad point bit ground from high speed steel will last about forever.

I think the Drill Doctor is a great idea. I wish I had one.
One other justification for one of these is that you usually only use a few bits from a set. If you go and buy replacements for the few that are dull you pay way more per bit than you would for a set.

I can sometimes get a bit sharp on the grinder, but it’s trial and error.

As far as knowing the quality of the steel, some of the better bits will be stamped with HSS to let you know they are high speed steel, the basic standard choice. If a bit has been used very long after it became dull and overheated (visable by discoloration) it will not be much good for anything. Most likely will not hold an edge if sharpened.

I like to buy Cobolt Steel bits in sets from places like HF or TSC. They hold up extremely well and are the very best for drilling stainless steel.

One way to test the hardness of the steel in a drill bit is to try to file the end of it with a cheap file. Good steel is harder than a cheap file and will round off the teeth on the file.

-- Michael :-{| “If you tell a big enough lie and tell it frequently enough, it will be believed.” ― A H

View Whiskers's profile

Whiskers

389 posts in 771 days


#5 posted 12-15-2012 03:56 AM

lol crank, but I’m not sure I want to kill my files. Than again, my files are antique too, so that probably won’t work with what I have on hand, they probably wouldn’t qualify with what you define as a cheap file. Guess I’d have to go to HF to buy a cheap file. TSC? Tractor Supply? The cobalt drills bits are extremely expensive, and I’m mostly interested in working with wood right now. Interesting enough, I have no brad point bits, my father never bought any even though he worked only with wood. I can only assume they weren’t invented in his lifetime or he would have had them rather than standard twist drill bits. He died when I was 17. I been websurfing various places getting a feel for the price of them, think I want a set but will probably watch and wait awhile and see if I can’t pick up a sale item from someone like rockler, woodcraft, amazon etc. I didn’t know harbor freight carried cobalt steel bits, seems kind of high end for them. I do know that the bits I have are useless for drilling steel of any kind. I’ve tried in the past and it a no go. Now it may be they too dull. It didn’t seem to damage them, it just wasn’t possible. They do fine thru wood though. I would like to be able to drill thru steel. Not necessary for any super stainless titanium type alloys, but for instance into my utility trailer to add features. Pefect example is my new tractor supply trailer has the license plate mount in a really stupid place that as soon as I hit a good bump, the license plate and it’s sturdy plastic mount will probably go Bye Bye. That definately could use a revision.

View gfadvm's profile (online now)

gfadvm

11479 posts in 1434 days


#6 posted 12-15-2012 04:02 AM

Whiskers- Couple of thoughts on drilling steel: cutting oil is definately worth the effort and slow speed is your friend. High speed hand drills do a poor job in steel and usually wind up ruining the temper in the bit from overheating.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View bandit571's profile

bandit571

7475 posts in 1428 days


#7 posted 12-15-2012 04:07 AM

I’m not sure, but doesn’t drill bits for drilling steel use a different angle at the tip?

-- A Planer? I'M the planer, this is what I use

View Whiskers's profile

Whiskers

389 posts in 771 days


#8 posted 12-15-2012 04:11 AM

lol, yeah glad, I know that now, didn’t know it when last I tried to drill steel which was a long time ago. Web is a wonderful place, you can learn anything from it. But still the bits I have didn’t even dent it. They are visibly dull. That why I’m asking about this. I got all these old antique twist drill bits, and I want to find out whether I should refurbish them to make them good, or just splurge and buy new. A drill doctor is about $100, that a alternative, a new set of good bits is also about $100. Considering all bits dull, well the math is simple if I have good bits.

View crank49's profile

crank49

3506 posts in 1715 days


#9 posted 12-15-2012 04:12 AM

True, the cobolt steel bits are spendy when bought from a machine tool supplier, but TSC (yes, Tractor Supply) often have small sets, 1/16 up to 3/8, for $10. A nice full 1/16 to 1/2” x 64ths set in an indexed metal box from HF will set you back $40 to $60, but thats way less than machine tool supplier prices. The quality is probably not up to machine tool standards either, but they are really good by HF standards.

I just got a TSC trailer this last summer. Ditto on the Liscense bracket.

-- Michael :-{| “If you tell a big enough lie and tell it frequently enough, it will be believed.” ― A H

View Grandpa's profile

Grandpa

3203 posts in 1420 days


#10 posted 12-15-2012 04:15 AM

gfadvm is giving good advice on spped and drills. If a drill is running the correct speed and it is sharp, it will cut and you should see longer pieces of metal coming from the drilled hole. If you see dust or very small fragments then you are usually running at a high speed or you need to sharpen the drill. With that said you have to run smaller diameter drills at a little faster speed than the larger diameter. The larger drill goes further (outside diameter) than the smaller drill in a revolution. I have found that good drills are sometimes a shot in the dark, especially on the least expensive end. I bought a Harbor freight set about 25 years ago and I still use them. They were pretty good. I have bought other lower end drills that were nopt so good. They a known brand on them too. Usually more expensive means they should be better but…..it can be a shot in the dark there too.

View Whiskers's profile

Whiskers

389 posts in 771 days


#11 posted 12-15-2012 04:23 AM

lol, well my bits when put against steel just kind of make a little polished dot at the moment where I point them, no shavings, no dust, nothing. I used to watch my dad alot as I grew up, He sharpened lots of stuff and I watched him. He was quite crafty, made violins. LOL, couldn’t play one. I swear he was tone deaf. Sounded like a cat caught in machinery, but he made good violins cause when others played them they sounded beautiful. So I saw and learned about sharpening some things. But for the life of me, I never seen him sharpen a drill bit, and from what I know he didn’t have equipment for it. He never had a bench grinder for example which is one way to do it. But here I have all these old well used twist bits.

View Whiskers's profile

Whiskers

389 posts in 771 days


#12 posted 12-15-2012 04:50 AM

Okay, I think I have made a decision, good bits are expensive. Very expensive. Crappy bits are cheap. I’m going to continue watching and waiting for a good set of brad point bits to go on sale cause I have none, and that what I need since twist bits tear out bad as they go thru wood. As for the twist bits and spade bits, I’m going to research sharpening methods and put the camel on the drill doctor. I’m also going to wire brush those spade bits to clean them up. Meanwhile the spade bits seem functional, but they are messy when they tear thru. I’m going to also put the camel on the new desiign bosch spade bits, they seem really good. They only about $30 normally, but might as well let that camel work for me and see if I can’t get them for $20. Historically it shows it very possible. The Bosch spade bits have a edge like a brad point to cut the outside of the hole first so there is little tear like with normal spade bits. The reviews are really good on these. If the camel comes thru I’ll have new tech bits for a good price, if not, I’ll eventually have sharpened up old good steel spade bits. I really also need to survey the bits to see if I’m missing any important sizes. I have quire a few, so might be surprised.

View Rob's profile

Rob

407 posts in 1815 days


#13 posted 12-15-2012 05:02 AM

gfadvm, I think the manual mentioned it could sharpen 200 bits, but if it handles even more, that’s great!

Whiskers, you could probably use a grinder or Dremel; the Drill Doctor just makes the job easier and helps ensure you get the proper angle on the tip.

View runswithscissors's profile (online now)

runswithscissors

1230 posts in 769 days


#14 posted 12-15-2012 08:31 AM

I agree, cobalt bits are best for steel. But it doesn’t matter what the metal is, a dull bit won’t cut. Even aluminum needs sharp bits. I often drill stainless, and always use cobalt. In an emergency, there’s another way if you don’t have cobalt, but won’t go into that now. And Drill Doctor is good. Haven’t tried other systems, though I do sometimes sharpen by hand/eye, but it’s hard to get consistent results. As for spade bits, many now have spurs to scribe the circle (way better than the old type), and some kind of fancy grind to provide relief. But how to sharpen them? Before that type ever came on the market, I started sharpening regular spade bits with a rat tail file or chain saw file. I try to use a file with a diameter that spans from the outer perimeter to the root of the point. I then file a hollow (half circle, more or less) in between the edge and the point. By tilting the file a little, I create the necessary relief. It’s possible to sharpen this way and get very nice sharp spurs, and the bits cut far faster and cleaner than a regular spade. Almost as nice a hole as a good brad point. Thing is, I can take a new spade bit and file it this way in about 10 minutes. When they get dull it takes about 2 minutes or less per side to sharpen. I’m convinced they perform better than the patented ones. (I’m not thinking about the Bosch, as I haven’t tried them). Oh, to control break out at the end, either use a backing board that you drill into a little ways, or drill just until the point starts to show. Then flip over and drill from the other side, using the little hole as your target.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View Whiskers's profile

Whiskers

389 posts in 771 days


#15 posted 12-19-2012 12:37 AM

thanks Artie, I’ll check those out next time I go to the library, I’m on dialup at home so youtube is kind of a no go. But I get to the library every week or two anyway. I probably would have found these eventually on my own when I started seeking the info out, but thanks for saving me the time. I pulled out one of them decrepit bits the other day, it was a 1/4 inch and it is all rusty, and corroded looking and at first glance you’d think no way, it going to cut, it should be thrown in the trash, but it went thru the 3.5 inch of a 2×4 4 times with no problem. I imagine if I sharpened it than I would have been even more pleasantly impressed. That’s twice I’ve used these nasty looking things and they performed beyond my expectations. They must be made of something decent to be holding a edge as bad as they look.

showing 1 through 15 of 18 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase