Drill Press – Speed/RPM

[18rabbit]

I got my hands on a used drill press. Been googling but can’t find any reference for appropriate speeds to use for drilling. I need to make countersink holes in 1/4-in angle iron for #14 wood screws, about a 1/4-in shank w/countersink head. My choices are 2600, 1600, 900, or 500rpm.

 

[Bondo]

Re: Drill Press – Speed/RPM

When in Doubt,........Slower is Better.....<br /><br />You're less apt to Burn up your bits.....<br /><br />BTW,..... Oil is your Friend,.... Use Plenty of It........I use ATF,....

 

[18rabbit]

Re: Drill Press – Speed/RPM

Thanks, Bondo. What is ATF? I have a can of cutting oil around here somewhere, is ATF better?

 

[cpj]

Re: Drill Press – Speed/RPM

ATF= automatic transmission fluid,I think.

 

[one more cast]

Re: Drill Press – Speed/RPM

Any lube you have near by will be just fine and yes ATF is auto trans fluid. I use everything from wd-40,kerosene,rapid tap,spray grease,motor oil to 90 wt. gear lube. You will be suprised how long a bit will stay sharp when lots of lube is used. My (change the belt to change the speed) drill press stays on the slowest speed all the time. But the rule is bigger slower, smaller faster.<br /><br />EDIT: 1/4 - 3/8 = 2000 rpm (from a chart I found online.)

 

[Paul Moir]

Re: Drill Press – Speed/RPM

I found this one:<br /> http://images.meredith.com/wood/images/pdf/speedchart.pdf <br /><br />My drill press has the following chart:<br /><br />Wood<br /><br />3050 3/8<br />2050 5/8<br />1390 8/7<br />900 1-1/4<br />570 1-3/8<br /><br />Aluminium/Zinc/Brass<br />3050 7/32<br />2050 11/32<br />1390 15/32<br />900 11/16<br />570 3/4<br /><br />Iron/Steel<br />3050 3/32<br />2050 5/32<br />1390 1/4<br />900 3/8<br />570 1/2<br /><br />That one's a little conservative though. I use old L/U lube all the time. It makes a sticky mess but it runs great. Never tried ATF though.

 

[Bondo]

Re: Drill Press – Speed/RPM

I use everything from wd-40,kerosene,rapid tap,spray grease,motor oil to 90 wt. gear lube. You will be suprised how long a bit will stay sharp when lots of lube is used.

Ayuh,........<br />I was going to say something like that,........ <br /><br />I usually use Whatever 1/2 full oil bottle that I can reach,.... Reguardless of What's In It......... <br /><br />I use ATF because it's got alittle "Grab" to it,... As in it's used with Clutches......<br /><br />Don't use something Toooo Slippery, like some "Teflon" lubes or things like That........... <br /><br />It's More a question of Heat Removal,.. than Lubrication............<br /><br />A Steady Stream of Water Works Pretty Good Too.......

 

[18rabbit]

Re: Drill Press – Speed/RPM

Thanks, guys! Paul, I looked everywhere for a chart like that, couldn’t find it anywhere.<br /><br />I haven’t been this excited about a power tool in a long time. Snagged a Jet bench top (yeah, right!?!) drill press (120/240v - 40amps) off of craigslist for $150. The kid selling it (a mechanical engr) is moving to the east coast, tossed in a machinist’s vice and one of those precision milling vice/stage thingies with all kinds of micro controls and scales and meters and precision crap. Don’t have a clue what it’s for, weighs about 30lbs. I can set it on the kitchen counter and twist little knobs for hours, scootin’ the salt shaker a fraction of an inch at a time. Never had an interactive paperweight before.

 

[snapperbait]

Re: Drill Press – Speed/RPM

Dang, Rabbit.... You made out like a bandit!... <br /><br />That ain't no paperweight... Cross-slide vices are sweeeet for little milling jobs..

 

[18rabbit]

Re: Drill Press – Speed/RPM

Oh, lordy! Snapperbait, now that I know what it’s called I looked it up. It’s selling online for $675!!! It’s this one, the small, 8-in, 40lb’er paper weight.<br /><br /> http://www.palmgren.com/palmgren/p-mt-crosssliderotarytables.html <br /><br />Obviously, it needs to be taken apart so I can see what makes it work.<br />

 

[Bondo]

Re: Drill Press – Speed/RPM

You're 1 Lucky rabbit,.............. <br /><br />That's a Steal of a Deal on a Really Cool piece of Equipment,........... <br /><br />Is Your's a Rotary cross slide like in the link,..???...

 

[18rabbit]

Re: Drill Press – Speed/RPM

It’s the same as the 8-in 32803 in that link, cross slides and rotates, except it’s green and has higher quality cranky knobs that are cast wheels with a bronze crank handle and hubs with a 1/1000-in scale machined into it. The 1-deg rotation scale is machined into the lower table, has a brass indicator. “Palmgren” is cast into the bottom of the base. Woman is demanding it be removed from the table. She’s not buying into the idea it’s a salt and pepper shaker holder…we should never have allowed women to go to college.<br /> <br /><br />I think the diff for the new Palmgren stuff is maybe it’s made overseas. From what I was just reading Palmagren used to be made only in America, but now some of their tools are “international tools”. I think that means “not made in America”. The casting, table, spec, etc all look identical.<br /><br />Tool quality is the reason I jumped on the Jet drill press. It’s an older Jet model, 13R, made in Japan before Jet was merged into the WHM Tool Group (Wilton). The build quality and machining of this tool is a thing of beauty. The crank to lift the table has a small gear box on it, literally moves like silk, you can’t feel any mechanical movement at all as the table floats up or down. The chuck is only 13mm (1/2 in) but the knurling on it is exquisite. New drill presses have good stuff like variable speed control but they are nothing like the build quality of the older tools.

 

[one more cast]

Re: Drill Press – Speed/RPM

The formula for HSS drill speed is CS (cutting speed) times 4 devided by drill diameter. The CS for mild steel is 100 so the correct speed would be 1600 RPM's for your project.

 

[Limited-Time]

Re: Drill Press – Speed/RPM

No faster than 900 RPM, from the voice of experience. When drilling steel or other ferrous metals Speed Kills!! Speed=heat, the harder the material your drilling the slower the bit speed you’ll need to keep the drill bit from burning up. Hardened tool steel and heat are Mortal enemies. Keep it slow and cool and you will surprised how long a good drill will hold an edge.

 

[Mark42]

Re: Drill Press – Speed/RPM

Most of my drilling is done at 690 rpm with 1/4 hp motor. Be aware that a motor geared down that low will spin whatever you're drilling into if it grabbs, even with the work piece held with vice grips, etc. Just be aware that it's not just your eyes you need to protect. <br /><br />If it is a bench top model, don't use it without first bolting it down to the work bench. Don't ask why I say that, just believe me, it's a good idea.

 

[18rabbit]

Re: Drill Press – Speed/RPM

Thanks for all the info, guys. After OMCs msg I googled for “cutting speed formulas” and found all kinds of info new to me. Also found some good info regarding the color of the metal shavings. For steel, if they are blue, you’re running to fast. If they are straw colored, you’re close to the max rpm. Ideally, they should be ‘steel’ color. Steel shaving cannot turn black.<br /><br />Mark, years ago I experienced the torque of a slow speed drill press. So powerful was that experience that I won’t even touch any power tool without knowing the direction of rotation. Funny how such experiences never leave one’s memory.<br /> <br /><br />Based on all of the advice I think I’ll just set the belt for 500rpm and let her creep on thru while drowning in atf.

 

[Scaaty]

Re: Drill Press – Speed/RPM

Use Kerosene on Aluminum........

 

[Moody Blue]

Re: Drill Press – Speed/RPM

Generally you will find that a SLOW rpm will give you a much better result when using a countersink tool. Faster rpm's often result in tool "chatter" which leaves a rough irregular surface finish.<br /><br />Don't look for the color of the metal trailings as an indication of proper speed. Proper drilling is a combination of rpm AND feed-rate. If the trailings are small chip like pieces, either the rpm is too high or the feed-rate is too slow for the rpm. Continuous spiral trailings indicate the proper combination of rpm vs feed-rate for the given material and bit size. Most people are afraid of applying too much pressure when drilling metals. The longer the bit spins against the material the more heat builds up. In extreme cases, this heat causes a surface hardening of the material being cut making it that much more difficult. Use a lubricant and clamp the work piece down as mentioned above.<br /><br />The best lubricant I have found for cutting/drilling/tapping aluminum is WD-40 hands-down. Varsol come in a close 2nd.