Drill Press RPM for steel

[easygo]

I used to meddle with hand sharpening drill bits but never was able to get a good enough result for serious drilling in steel.

 

[tcreeley]

I've got an old Atlas drill press that my father-in-law gave me. He was a GE machinist for 30 years.
On mine I can adjust speed by shifting the drive belt up and down on the pulleys. It seems to me that you can just replace pulleys/belts until you set it up to run as slow as you want,
I sharpen my own bits- I'm cheap. I don't do a good job, but they work for what I do. I'm not the best with safety- bunch of times I've lost hold of the piece I'm drilling and had it spin around! Can hurt!
I am always impatient.
As for cutting oil- I read this in an old blacksmithing book- try bacon fat. I pour the hot fat from just cooked bacon into a small glass jar and let it cool. When I want to use it, I lift the jar up onto the drill bit in the drill press. Works great, no lingering oil mess, cuts well. And my cats leave it alone. It lasts for years and in the coolness of my shop - it always is hard so I don't worry about spilling it.:laughing:

BHD- I never saw one of those before, what a great tool!

 

[robs660]

So where do you get or how do you get a drill press tat will run at 200 rpm or lower?

 

[SandburRanch]

So where do you get or how do you get a drill press tat will run at 200 rpm or lower?

***************************************************
Here ya go.

Build a Low Speed Drill Press

 

[DanD78]

So where do you get or how do you get a drill press tat will run at 200 rpm or lower?

I found mine on e-bay. They are on there used all the time. I gave $200 for this Johansson tool room drill press. Has a gear drive head and power feed.
I would not trade it for a new one. Most good drill presses will be 3 phase. Don't let that scare you off. Phase converters are easy to build or buy.

Dan

 

[ultrarunner]

I would run a 1" drill through a 1/2" pilot hole on a large press at 320 for steel with coolant...

One bit would last morning to noon...

The problem with lots of drill presses is they flex too much, i.e. are not rigid...

Also, many presses are geared for wood work with higher speeds.

Here's a link:

http://www.ibiblio.org/twa/info/drillSpeedChart.pdf

 

[crazyal]

Sooner or later you are going to drill a hole with a hole saw. Something larger than the 1" you think is your max. Hole saws last a very long time as long as you go slow and you keep them lubricated. I have hole saws that are 15 years old and been used 100s of times. I bet I have over 50 different sizes up to 8". I never drill with them at speed over 100 rpm.

 

[ultrarunner]

Just checked the slowest spindle speed on my J-head Bridgeport is 80

Pulled out my original operators manual and it lists the following feet per minute for steel:

Feet Per Minute..................One Inch Drill RPM

30 (Steel Chrome Nickle)................115

40 (Steel High Carbon)...................153

60 (Stainless Steel).......................229

80 (Steel Low Carbon)....................306

 

[lostcause]

So where do you get or how do you get a drill press tat will run at 200 rpm or lower?

the easiest way to answer that is by telling you where you won't get one - sears, lowes, home depot, etc. the stuff they sell just isn't targeted at the people looking to drill 1" holes in heavy steel.

there's tons of old tired iron still floating around from back when we used to make things in this country. if you aren't near an area where that stuff is plentiful, then you also have the option to look for new or newer used china/tiawan made machinery.

companies like jet, harbor freight, enco, grizzly, and many others sell variations of the same machines that while often lacking in fit, finish, and polish will generally do the job. they also often do require some cleaning and adjusting before using when new, sadly.

i was in the market for a drill press to do the same size holes a year ago. there was nothing to be found used, but i did manage to find a used mill/drill for a reasonable price instead. it isn't as user friendly as strictly a drill press, but it sure does open up a lot of new avenues for fabrication.

to get back on track - 150 rpm for that size. 250 absolute max, and that's only if the machine doesn't go slower. if it won't go to 250 or less, i wouldn't even bother wasting the bit.

 

[5030]

Hay... i happen to like my Drill doctor. its saved me many times over its cost in drill bits. If i had a professional shop, than things might be different. Then again, i was introduced to the drill doctor by a machinest that worked at Boeing.

Like I like my chi-com saw.....:thumbsup:

I had a Darex at one time. Gave it away.

Just so long as the 'doctor' wasn't a proctologist......