Drilling/Cutting Speeds

[bajajoaquin]

I haven't been around here in a while, but I thought I'd poke my head back in and ask another question.

A while back, I asked some basic questions about my new (to me) drill press. It's 1hp, and has a speed range down to 160 rpm. Basically, I leave it at 160 all the time. I mostly drill mild steel, with a few holes in wood blocks from time to time. Bigger holes get tapping fluid, but mostly I run it slow to keep temps down.

Similarly, i have an HF 4x6 band saw and I always run that on the lowest speed.

The question: Is there any down-side to drill/saw life by running them at the slowest possible speeds all the time? Or am I just giving up the speed of the job?

And I appreciate the advice and concern given when I bought it a while back. I still have all my fingers, limbs, and all blood has remained inside my skin (at least with regard to using the press).

[mikecwik]

You should run your drill press at different speeds because that is the best way to do it.A larger cutter generally needs a slower rpm and a smaller cutter a larger rpm. Every machine is different and a guy needs to experiment with speeds feeds and grinds.

[FrankClassen]

Yes, speed plays an important role while cutting or drilling. As per mikecwik said larger cutter generally need a slower rpm and smaller cutter requires larger rpm. One can get some more information regarding drilling and its speed at this website. Also the quality of the drilling machine matters a lot. The better the quality the better are the results.

[bearston]

Slow doesn't work well with all materials. If you're not sure, use a drilling chart, look here:

https://www.fnal.gov/pub/takefive/pd...peed_Chart.pdf

A good place to start, notice wood and steel speeds, you'll figure out what works best for you. I go slower in steel than the chart suggests, but that's what I learned...if it squeaks, it's too fast. I always try to use high quality HSS drill bits and I sharpen them myself.

sorry to resurrect old thread, but this stuff is important.

[Dumitru Ivanov]

It depends on a lot of factors, but most frequently the ideal speed is the medium speed. Safe and reliable.

[MAC702]

It depends on a lot of factors, but most frequently the ideal speed is the medium speed. Safe and reliable.

Welcome.

However, um, no. "Medium" is a relative term with a different speed on different machines. And in many shops and for many projects it is very frequently NOT the correct speed.

Use a drill chart that gives you the speed in RPM, and set your machine as close to it as you can, for each material and drill bit size.

[Northweldor]

Welcome.

However, um, no. "Medium" is a relative term with a different speed on different machines. And in many shops and for many projects it is very frequently NOT the correct speed.

Use a drill chart that gives you the speed in RPM, and set your machine as close to it as you can, for each material and drill bit size.

I agree, and would add, if you can't get your speed low enough to drill according to table, then use cutting lubricant.
Messy, but extends life of drill bits and reduces sharpening enough to pay for itself.

[djacob]

So, don't you have the option to choose the power level/speed level? I think the speed is managed from your motor settings...

[Northweldor]

So, don't you have the option to choose the power level/speed level? I think the speed is managed from your motor settings...

Not "motor settings"...
For most of us, the speed is managed from pulley settings, as few have gear-driven drill-presses. I have a 12-speed 20" floor model with 3/4" chuck, and use cutting oil on all drilling above 1/8" thickness in steel, which is what I drill most.

[monckywrench]

One thing every drill owner (any drill!) should buy is a set of machinists center drills. They are also used in milling machines because even on a rigid mill conventional twist drills walk quite a bit.

Link shows examples. You can get them at any industrial supply or online.

https://littlemachineshop.com/produc...ProductID=4859

Also get a quality prick punch and center punch if you don't have them.

Even little drill presses can turn out good work with patience.

[GOPAL123]

Speed equals: 80 surface feet per minute in 100 Brinell hardness material and the speed should be reduced 10 surface feet per minute for each additional 50 points Brinell hardness. Feed and speed rates: should be reduced up to 45-50‰ when drilling holes deeper than 4 drill diameters.

[MAC702]

Speed equals: 80 surface feet per minute in 100 Brinell hardness material and the speed should be reduced 10 surface feet per minute for each additional 50 points Brinell hardness. Feed and speed rates: should be reduced up to 45-50‰ when drilling holes deeper than 4 drill diameters.

Is this your personal experience or is there a source for this info? Looks like good stuff to know.

[Northweldor]

Is this your personal experience or is there a source for this info? Looks like good stuff to know.

It's from this website, and should have been credited.

http://www.ctddrill.com/drillFeedSpeed.php