Drilling steel- what am I doing wrong?

Chiro75

Chiro75

Joined
Feb 4, 1999
Messages
5,786
I have always had a lot of trouble drilling steel, and I am tired of it. I am using a relatively cheap drill press and I do believe I set the pulleys so it is at its slowest speed. For drill bits I am using whatever cheapo bits they have at Lowe's. No lubricant. Steel is hot rolled 1084 from Kovals. Sometimes I can use a fresh bit and it just bites into the steel, but I don't think I've been able to make more than one hole with a fresh bit. Usually the bit breaks the surface and starts squealing without going anywhere. I thought maybe I was heating the steel up too much when I grind, so I tried drilling before grinding and that doesn't seem to make a difference. So:

1) What am I doing wrong?

2) What should I be doing that I am not?

3) Is there a preferred bit, and where would I get it?

Oh, my steel is 1/8" thick and I also generally just drill 1/8" holes for pins...I would probably drill more 1/4" thong liner holes but I don't like buying a new bit for each hole. Obviously I am doing something fundamentally long.
 
Quote"For drill bits I am using whatever cheapo bits they have at Lowe's. No lubricant. Steel is hot rolled 1084 from Kovals."

I think you answered your own question.

I use good bits, but by no means top of the line. I get the TIN coated bits for most regular tang drilling. I use LPS Tap All for a lubricant, as I can't stand the smell of cool tool. But you do need a good lube, and don't lay on the drill press handle till the smoke starts pouring out. Drill for a few seconds and raise, add lube if needed, and repeat. You can tell when you are overheating, the object is to not do that. It's like driving your car/truck without any oil in the engine, the way you are doing it now. :eek: ;) :D
 
You are drilling steel that is not fully annealed, and may be work hardening as you drill it. Drill as slowly as possible (low r.p.m.'s), use a sharp drill (get a Drill Doctor if you want to sharpen them) and use a lubricant such as Cool Tool II. Bottom line is you are drilling steel that is partially hardened.
Make sure you are using drills made for drilling steel, not wood. I'm not certain but I think there is a difference.
I just drilled through 1/4" 5160 with a 7/64" bit, and while I could tell the 5160 wasn't dead soft, it still drilled easily. Some of the forgers around here can tell you how to soften your 1084.
 
I am using whatever cheapo bits they have at Lowe's
there you go and said before. I drill a lot, not always using lube
but I do go slow backing off to let it cool. if you get smoke and
are not using cutting lube then you've just smoked the
temper out of the drill bit, if it had much in the cheap bit to
stat with.
You can just get the bits that are marked high speed, at your Napa store.
high speed doesn't mean what it implies. if you can get some (tap free) fluid it works great, smells good, and not greasy, 2 more cents
 
I use colbolt drill bits. My drill press speed is about 1/2 way on teh pullies, I have no idea what the rpm is. I ususally dont use lube but I go slow and cool the bit when I have to
Jack
 
I had the same problem a while back, trying to drill 1/4" holes in a tang. i went to Harbor Freight and got a 12 pack for about $3 i think. I went home, tried the first one, and it just barely bit into the steel, then wouldnt go any further, figured what the heck i have 12, so i took a new one out of the pack, heated up about the 1st half inch to non magnetic and quenced in transmission fluid if i remember right, drilled both holes in no time with it and several since with the same bit, now i have a bunch of extras, just in case. :D
 
I also use the Harbor freight cheapos.
They work fine on everything from 5160 to S30V.
I get plenty of use out of all of them except Ats34 and S30V I use a new bit every 9 holes or so.
Just remember to let the bit do the work use moderate pressure.
When it heats right up either sharpen it or toss it.
 
Out of all the steels I have used, I have had the most trouble drilling into 1084, my theory and the general consensus when I asked about it before, is that a lot of the 1084 being sold is not fully annealed. I bought some cobalt bits, and I have drilled probably 60 or 70 holes with my 1/8" bit, and it still drills fine, even in the 1084 I was having trouble with before. If it makes a squeeky noise when you are drilling, odds are the steel is too hard. you can either anneal the blade, or buy better bits, I highly recommend the cobalt bits. I got mine from TKS.
Kyle Fuglesten
 
I also use a very cheap, Made-in-China throw away drill press that still functions well. My cheap drill bits are actually average quality ones made of HSS. They are quite hard to ruin the temper, as compared to some carbon steel ones. I just didn't think they made carbon steel drill bits anymore. I drill up to 80 holes for each 1/8inch drill bit at about 1450rpm. I then can get another 40 holes or so just be touching up the bit with an EZELAP diamond sharpener. The bits only cost 80cents but I'm dead cheap.

Is is important to also ensure that the drill press table is dead straight. Drilling skewed holes in softer material is fine, but not on steel. Everyone has already said that its likely the steel is semihard and needs to be fully annealed. Even on semi-hard steel you should be able to get a good bite in. The spines on my edge quenched blades run between 42 and 46HRC and I can still drill into it (using slower speeds).

Try everything. Check the table, check the speed, check the bit (could be a defective set of bits with a ruined tip), anneal the steel, centre punch for each hole, go slow, lubricate well, keep it cool. Try cobalt, but I presume its worthwhile trying everything else, though because they can start to get expensive if you use a lot. If it squeaks, back off, lube. CLAMP YOUR STEEL, you don't want no helicopter action here.

Good luck. Cheers.
 
I can't believe all you guys left out the most important part... :p

I start each and EVERY hole with a #1 or #2 combination bit, mostly #2s. They are cheap, short, double ended and have absolutely zero flex. It is the only way to start a hole that you wish to be accurate. So, start a hole with the combo bit then finish with a regular cobalt drill bit of the size needed and use coolant if necessary. The biggest holes I regularly drill without coolant are 13/64.

I pull up before the countersink portion hits the blade if I do not wish to have a countersunk hole. Nearly all holes I drill end up getting very lightly countersunk anyway even if it's just to deburr.

Honestly, for small holes I rarely need coolant when drilling stainless steels. Maybe the 1084 is different. Anyhow, just my take on it. :)
 
I use the hss jobber drills from MSC. They are nitride coated and work great. It's better to spend the money on good drills and buy them once in a while rather than once a week. I'm too poor to buy cheap. It means spend the money, buy it once. Cobalt drills are more expensive but they might last longer. The angle that the drill is also sharpened at makes a difference. Try using a center drill first, it might help.
 
Peter, those short drills are called center drills. They are used to start a hole and they won't "Walk" like a longer drill will. They do make them in carbide but they are $$$$
 
Always use cutting oil and penetrate the steel very slowly, pulling the bit out after drilling only a few thousanths at a time to let it cool. Also, for larger holes, drill the hole first with a smaller diameter bit. I often use three different sizes for one 1/4 inch hole.

Being impatient will ruin the best bits and always keep cutting oil on the work.

Roger
 
You can get cobalt bits at lowes, they're made by dewalt. They're not cheap though and I've had trouble here and there (2 of about 10)with them not drilling round holes. Had to take them to the bench grinder.
I've been getting by using WD40 instead of buying a regular cutting oil.
Yeah, I'm cheap.

Side note, sharpening twist drills on a bench grinder free hand isn't TOO big of a challenge. Its hard to get a point that really wants to bite in, but I can get them to drill round holes the size they're supposed to and they stay centered once they're cutting.You just have to either make a really good mark with the center punch or use a center drill.
 
My line of work requires me to drill alot of holes in many different materials (in addition to drilling holes in knives at home!) so here's my 2 cents. Resist the erge to purchase cheap imported drill bits. In the long run you will make money if you purchase wisely. My favorite bits are cobalt stubbies. They are about 2 inches long for an 1/8 bit. Secondly, the are split pointed so they will not "walk" all over the steel. The key to cobalts success is its ability to handle heat and heat destroys drill bits. I rarely use a coolant with cobalts. Now for HSS. These drills should be cooled as opposed to being lubed, although there are exceptions. A lubricant often times dosen't cool the bit as well as a coolant. Heck, I've used water instead of a cutting fluid for drilling holes. Oh yeh, never try to drill a hole with a dull bit. I bet if your knife gets dull you would make point to sharpen it before you use it again. A common problem encountered while drilling with a dull bit is what is sometimes called "slicking the hole." This is where the hole hardens and makes that sqeaking sound. This problem is best avoided with appropriate precations. A slicked hole is not easy to fix. I try to use preventive medicine like cobalt stubby bits with split points or with HSS, (also good to have split pointed) use some kind of coolant or maybe a real thin oil that can dissapate the heat as quickly as possible. I guess I'm starting to ramble on. I hope this helps alitte. Good luck!

Luke Smart
 
Smart2K,

I have encountered the 'slicking' problem while using worn bits, especially while trying to drill without enough coolant; cutting oil.

I have recently been using the 'Tap Magic' oil. It is very thin and seems to work well for my limited use.

I have read that cobalt actually gets harder with heat, however I have suceeded in burning some cobalt end mills at high speed.

Roger
 
Marvels Mystery Oil makes good coolant and taping fluid. Cheap and found at Wal mart. my $.02
 
I am starting to see what the problem is, you aren't using a punch and pritchel hole on simple carbon steel!:D



C Wilkins
 
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