Drill press speeds for steel?

[CJW]

I've never had the luxury of a nice drill press to drill steel but hopefully I can buy one soon as I'm done with high speed presses that scare the crap out of me. What kind of speeds should I be looking for to drill anything from 1/8"-1/2" steel and aluminum?

[Harold Phipps]

Look for a low speed of around 100 rpm.
You know you'll drill biger than 1/2", and you will probably want to use hole saws on the drill press if you can get it slow enough.
Lots of times I have my mill down to 60 and that seems fast.

[widmayer123]

The slower the better!!

[UnusualFabrication]

Originally Posted by CJW

I've never had the luxury of a nice drill press to drill steel but hopefully I can buy one soon as I'm done with high speed presses that scare the crap out of me. What kind of speeds should I be looking for to drill anything from 1/8"-1/2" steel and aluminum?

If i'm reading this correctly it sounds like your referring to the material size and not the drill size. The size of the material isn't going to dictate the speed and feed of the drill, the size of the drill and type of material will. Smaller diameter drills will run at faster RPM's than larger diameter drills. If I were drilling HRS/CRS with a 1/8" twist drill it would run at 2445 RPM and a 1/2" twist drill in the same material would run at 611 RPM. Most drill presses don't typically have the capability to dial in the exact RPM so just get it ballpark, feel the machine, and watch the chips. They'll tell you everything you need to know...

[Todd W]

Originally Posted by widmayer123

The slower the better!!

No, this is not the case at all.

You need to go the proper RPM for the hole size, and material.

Too slow like too fast can cause problems with wear on the bit, burning up your lubricant, and overall poor drilling performance.

There are some charts that's been posted here a few times.

[AIRZUKI]

CS x 4 / D = RPM


cutting speed multiplied by Four divided by tool diameter equals proper rotational speed of your tool bit

for a High speed steel drill bit cutting low carbon steel use a cutting speed of 100 , for alloy 70 or 80

[1TON73K5]

Originally Posted by AIRZUKI

CS x 4 / D = RPM


cutting speed multiplied by Four divided by tool diameter equals proper rotational speed of your tool bit

for a High speed steel drill bit cutting low carbon steel use a cutting speed of 100 , for alloy 70 or 80

the standard of 4 is the basic rule of thumb. I have found over my 20 years as a machinist that the standard of 4 in most cases makes for too fast of RPM. I tend to use 3.5 to 3.75. There is a HUGE amount of variables that dictate weather you can use a higher RPM or have to run slower, like rigidity, tool extention from your tool holder or collet, power of the machine, the list is long. Standard of 4 is a starting point, RPM calculation is not exact.

[trkklr77]

i have a decent sear drill press. 7,000,000 down to 250.


its been on 250 for then better part of 1.5 years now. 1/4-3/4 twist bits and 2" hole saws.

[I Lean]

My drill press goes down to 170 RPM, and that's where it stays most of the time.

I'll agree with the "slower is better" comment--not for the drills, but when choosing a drill press to buy. They'll all go plenty fast enough, not all will go slow enough.

[CJW]

Thanks guys. I'm not looking to get overly complicated with this as I'm just a hobbiest. I just wanted a basic range. What I've got out of this is that if I can get down to around 150-200 I'll be fine.

Thanks again.