Drill Press Help

I need to drill a number of 9/16" bolt holes in 1/8" thick plate steel planks that i have. I know little about milling metal, i assume you would use a drill press for this sort of thing. Do we have the equipment at DMS to make these cuts? Any general words of advice in this endeavor?

There is a drill press in the metal shop. I’m not sure how the selection of drill bits is though, I used my own when I had to drill some aluminum. I would suggest picking up a good 9/16" carbide bit, or at least titanium coated.

Heat is the enemy, as is excessive force. Go slow.

Given your lack of experience in this area, I strongly suggest that when you are at the space to do this, you find someone to provide you some guidance. What your drilling through, and with what will greatly affect how you need to proceed to do this safely.

The first thing you should do is perform a file test on your metal. If the file can’t cut the metal then it is simply too hard to drill with the equipment available at the space.

These are awesome, Harbor Freight step bits

If it’s a hole pattern, you’ll need a centerpunch, a scribe, a straight edge, and some calipers.

I usually also use a really small drill bit post-centerpunch.

As previously alluded to, you want to use a slow drill speed and some oil in the cut.

Thanks to all for the great info. Would anyone be willing to meet me at the space on Sunday to show me how to use the Bridgeport mill? Like I said, I’m just drilling simple bolt holes. I greatly appreciate any help, I’m kind of desperate with this

I wish I could volunteer to assist on Sunday, but I cannot be sure of my schedule, and I’m not that confident in my abilities, let alone helping someone else screw up, er, fix their project.
Read on for some pointers on maximizing any help you’re able to procure:

If you have not already so done, check out the “always available” training materials on the Bridgeport, in particular the manual


to familiarize yourself with the controls and at least skipping your way though one or more of the MIT training videos
http://techtv.mit.edu/videos/142-machine-shop-1
will help you be ready to maximize any assistance you’re able to procure.
These and more are available on the Machine Shop committee page: https://dallasmakerspace.org/wiki/Machine_Shop_Committee

Also, if you have not already, go ahead and lay out the pattern on the material, unless that’s part of the help needed.

Unfortunately, my weekend is already booked up, so I can’t help.

That said, since all you need to do is drill some holes, I suggest not using the Bridgeport since you aren’t familiar with it. You would be better off using the small drill press in the metal shop as opposed to the Bridgeport in the machine shop.

The wiki page has a link to an MIT video on drill press operations which should give you the guidance you need for drilling some holes. That said, the space does not have any 9/16" drill bits, we max out at 1/2". You will need to acquire a 9/16" drill bit with at most a 1/2" shank (the largest size our drill chucks can hold). Your best bet to find that is to go to CDC tools on Beltline in Richardson and buy one. Expect to spend about $10 for it.

With the step bits I posted, I’d be totally comfortable drilling 1/8" stock with my Makita cordless, they really do make a difference. I did it yesterday and I’ll prolly do it again tomorrow. 1/8" plate is cheap as dirt, no need to be bashful.
That said, CDC is awesome and you should go there, I got my Cobalt scribe there.

The bits your talking about are designed for sheet metal. By the time you get to 0.125" thickness you are really dealing with plate steel. The step bits that I own, have steps that are about 1/8" in depth before the next step starts.

All that said, you can usually get away with using these bits on 1/8" thick material, but I wouldn’t. A proper bit (American made) can be had for less then the Chinese set you linked to from CDC, so I actually think my option would be cheaper for the OP. And using the small drill press in the metal shop is no more difficult then using a hand drill with your step bits. In either case the metal should be clamped down so it can’t spin.

I tried the small frill press last night (see image) with both a step bit and a 1/2" bit. I center punched a drilled an 1/8" pilot no problem, but the little drill just doest seem to have the torque I need. It would clutch out with the slightest pressure. I could only get minimum shaving and after about 30 min of methodical drilling, I was only half way through the material.

Perhaps I was doing some things wrong. I like the idea of using a cord drill for this, it doesn’t have to be EXACT, just close. Keep the suggestions coming yall, thanks so much!

That press has pulleys in the top to control speed. You want the slowest speed it has.

You also need to drill slowly. I would expect to take somewhere between 3 & 5 minutes per hole at 5/8".

That drill press should have no problem drilling a 5/8" hole in 1/8" MILD steel.

If your not using mild steel you likely need a specialty bit, 135 degree split point, and potentially even needing to be carbide.

Did you run the file testI suggested?

Oh, you also NEED to use cutting fluid.

They are certainly not designed for sheet metal and I wouldn’t recommend them for such. They are designed

for drilling deep holes in plate steel the way you’re supposed to, without having to re-center your bits.

Starting out with a drill bit the size of your finished hole is asking for trouble. It’s gonna walk, or bind, or worse.

[quote=“Fre0n, post:13, topic:3837, full:true”]
They are certainly not designed for sheet metal and I wouldn’t recommend them for such. They are designed for drilling deep holes in plate steel the way you’re supposed to, without having to re-center your bits. [/quote]

No, step drills or Unibits, are most definitely NOT for drilling deep holes. They are for thin materials such as sheet metal, though they work reasonably well on thin plastics as well. Haven’t ever tried them on thin wood.

Here is the relevent text from the brochure from a major manufacturer of these drills; "Metal Drilling800.866.5740METAL DRILLING155Step Drill BitsIRWIN® UNIBIT® step drill bits are ideal for drilling holes in just about any type of thin material. "

source of above quote

I never suggested starting out with the full 5/8" drill bit size. I suggested the OP watch the MIT video on drill press operations, which provides all of the guidelines needed on marking, punching, and step drilling (with real actual drill bits) holes in plate material.

I must have been doing it wrong then. I was using fluid, but as i said previously, i wasn’t making much headway at all. The professional who originally cut the steel for me said it is mild steel and should cut fairly easily so it must be user error. Im not sure what a file test is, but i will look it up. He also said a step bit or full size bit would work, as long as i drill an 1/8" pilot.

The file test is simple. Use a file to try and cut an edge of the metal. If it cuts the steel is soft enough for our tools to be able to drill holes.

For your material you MIGHT be able to use your ‘step drill bit’, but those bits are not intended for anything but sheet metal.

Have you watched the MIT videos, I and @jast mentioned to you?