How powerful of a drill press do I need for high carbon steel?

[brynnb]

I'm looking at cheap stuff to get my first workshop built up. There's this:
http://www.amazon.com/POWERTEC-Speed-Baby-Drill-Press/dp/B004I6980A/ref=sr_1_15?ie=UTF8&qid=1313712689&sr=8-15

which has 2/5HP. One review says this is enough for even medium carbon steel, but in such a way that suggests it couldn't be used for high carbon steel (knives).

What do you guys think? Even if I took it slow and easy, would this be reasonable for high carbon steel? If not, what's the minimum HP I should be looking at?

[pkrankow]

Power isn't everything. How SLOW can it go? High carbon steel likes slow speed and positive feed to cut it well. When you are not cutting, you are hardening the surface significantly so cutting is more difficult.

http://www.harborfreight.com/5-speed-drill-press-38119.html

I have drilled annealed leaf spring with a HF benchtop press. Can't drill hardened leaf spring though. I do not consider this a good drill press, but it does get the job done.

I have seen hardened steels drilled, but that is a different class of machine altogether.

Phil

[MattBower]

It also depends what size holes you want to drill.

[fciron]

You need to go slow for larger holes and slower materials. Faster for smaller holes or softer materials. The drill press in your link offers speeds between 650 and 1300 rpm; that should be good for holes between 5/16" and 1/8" with high speed steel drills in high carbon steel (I'm assuming this is before hardening.) That's an approximate guess, YMMV.

[Glenn]

Do a search for a post drill. Hand cranked but they do a LOT of work.

[BIGGUNDOCTOR]

You can have a great drill press, but if you use crappy drill bits it won't matter how good the drill press is, and be wary of hyped bits with wonder coatings. I am a tool maker, and all of my drills are either just balck oxide, or bright finish HSS, and do fine. The main thing to look for is a tight quill with no slop in it, and a true running chuck. If the chuck is wobbly all you will get is wonky holes, and broken small bits. It isn't the horsepower that will get the job done, but the right bit. I drill hardened steels like taps at work all the time, but I am using solid carbide bits. Dad had an older Taiwanese drill press that did a great job. Look for a solid quill, chuck with little run out (more important the smaller the bit gets), a table square all ways to the quill, and a solid dive system that won't slip when loaded down. A lot of the new Chinese machinery has some really poor materials, poor manufacturing tolerances,and crappy casings. Look for a used USA, or Taiwanese made drill press. The Taiwanese have been making some good machine tools for the USA market for years. Even so, look for what I pointed out above, cause worn out is no good either.

[brynnb]

So it looks like the consensus is that it'd be fine for smaller holes with the right bits. Does drilling a smaller hole and then a larger one on top of it not really work?

Do a search for a post drill. Hand cranked but they do a LOT of work.

This looks like it'd be a really fun project to make, gingery style.

[ThomasPowers]

What you are hunting for is Rigidity and SLOWness when you drill metal. Most set ups are designed for woodworking.

I have two hand drills, one for wood the other for metal. At the same capacity the metal drilling one is way less than 1/2 the top speed of the woodworking one---but about twice as heavy. It will happily hurt you if you don't watch out!

[Frosty]

Yes you can pilot a hole and then use larger dia bits to drill (chase) a larger hole. The problem though falls on how stresses are fed to the bit if several conditions aren't met. The trick is increasing dia. correctly, many folk increase it too gradually, step it up at least 50% per chase. Yeah, the pilot is a drilled hole, the enlarging increments are "chased" holes. For example, pilot drill 1/4", 1st chase 1/2", finish chase 1".

Speed is critical, drilling ferrous it's hard to turn it too slowly so long as you're not hogging the bit till it jams. Dragging it is a killer, work hardens even mild steels and runs the colors (burns the hardness) out of the bits. What gets most bits is breaking through thin stock, it tends to bend over the final few thousandths and bind the bit. Listen carefully and you'll hear the bit closing on the final break through, this is the only time it's okay to let the bit drag slowly. It's only a few thousandths and it keeps from breaking bits.

Be sure the stock being drilled is solidly clamped to the table, any movement will shorten bit life and can REALLY cause pain if the work comes loose and starts swinging around the bit like a brush hog. Need a visual? Run over a roast with a lawnmower.

If the bit sticks, turn the drill off and back it out by turning the chuck backwards by hand. If you just pull it with the feed lever you'll dull the bit badly by breaking the sharp edge that's caught.

A post drill is a good option largely for two reasons, first it's hard to crank one too fast and secondly most have a feed to advance the bit at the proper rate. Advancing the bit properly is one of the gleaming secrets of drilling good holes, be it wood or an oil rig, it's rotation speed and down pressure that does the job or ruins the job and tools.

Frosty the Lucky.

[Spurrit]

So it looks like the consensus is that it'd be fine for smaller holes with the right bits. Does drilling a smaller hole and then a larger one on top of it not really work?

I "get" how desperately you want it to work. You can ask all the questions you want, and yes, if you do enough work, you can eventually punch through with a rock. Really, what you need to ask yourself is, do you want to make do with crap, or can you just hang on, watch Craigslist and yard sales, and save your pennies?

These internet forums create a ton of peer pressure. Everyone get to thinking they NEED all this crap. I bet 80% of the guys posting haven't lit a fire in a month! Same with firearms forums. When I'd meet some of those folks at the range, it was pretty obvious they spent a lot of time on theory, and very little on practice.
Not to say I'm some great smith or that I'm in the fire every day, (it's been friggin' COLD here, and I don't have a shop right now) but it's just kinda how things work, as I see it.
I STRONGLY recommend looking into a Shopsmith with a bandsaw attachment. Lotsa power, variable speeds, modular, and great bang for the hobbyist's buck. AND, since people are getting more and more useless, used ones are getting cheaper all the time! I got mine for $175, then went and test drove a truck to get it home, back when I had an Explorer. :rolleyes:

[Tom Allyn]

Check Craigslist for drill presses. They're a dime a dozen (well not literally). Pass over all the home-store junk. Find an older industrial unit, even a benchtop unit is fine. They come up fairly often so keep your eyes open for a couple of weeks.

Carbon steel can be drilled easily so long as you anneal it first. High speed steel bits will do fine if you take it SLOOOOOOW. And don't forget to use cutting fluid. For even better results try cobalt bits. They're not just coated like titanium bits are. You can sharpen your cobalt bits. And sharp cobalt bits will even drill stainless steel.