Is this a new drill press tip ?

[autoclassicnut]

I worked part time at a welding shop a couple years ago and the boss had me drill holes in a bunch of 1 1/2" x 1 1/2" x 1/8" angle iron for a customer. Well I had nothing but trouble as the bits were getting dull and heating up and it wasn't going well.
This old timer that I'd worked with at the sawmill years before (he was a millwright) welder fabricator for several years, Told me to take a break... I came back and he had them all drilled and stacked! I was in awe... He got more drilled in 15 minutes than I had in an hour, using the same bit that I was.
Wanting to know how he did it , I asked him... He laughed at me "I'll tell you but I'll have to kill you"... (we have always gotten along great), Well I told him I'd risk death, so said "To get rid of that darned cutting oil".
I asked him why , He said " It just heats up the bit because the drill slips on the metal." I had never heard of such a thing, But then I asked him if the drill was going too fast, and he said "the speed is fine".
Try drilling with a little spray bottle of water next time, you won't believe how it'll cut like butter! Any one else use this trick?

[ksp]

Never have but I will!!!

[kbs2244]

Old timers have used anything wet. (Use you imagination.)
The idea is to keep the temp down.
You do need to go a lot slower with metal then with wood.
That is a big problem with guys buying these $50 and $75 drill press for metal work. They are just too fast. They need a jack shaft set up to slow them down.

[Herb]

I recently built a lumber rack and needed to drill 75 1/2" holes in the 2"x 2" x 3/16" galvanized angle iron that I used. I only used some cheap 30w oil, kept the speed down to ( I think) 120 rpm's, and it did fine with the same drill bit. Some cutting oils can be to slick and that turns into a very frustrating experience. If you ever want to have some fun, try using a synthetic oil as a cutting oil- now that's FUN!

[autoclassicnut]

Herb ;

I've never tried it but I can imagine that you can''t get it to bite into the metal ...right?

[Deltarat]

I used to get a cutting liquid from the local machine shop that they used in their drill presses and band saws. It was not oily and you mixed it 50-1 with water. I think it really was a rust inhibitor and the water was doing all the work.

[kidney]

Someone on here mentioned using a 50/50 mix of tranny fluid and WD40. I tried it and it seemed to work pretty good. I don't really drill enough to try everything out there, so the tranny/WD40 was easy enough since I usually have both on hand.

[zr1nsx]

Most metalworking coolants today are a synthetic blend of 95% water and the rest is mix. Most failures from drilling holes in steel is the drill bit spinning too fast which creates the heat, and then adding oil which in effect is quenching the steel your drilling. This process work hardens the steel your trying to drill. Slow down the drill, or better yet, drill a much smaller hole as a pilot hole. If you look at the end of any common twist drill, there is a web directly between the flutes (looking at the drilling end). The larger the drill diameter, the larger the web. If you start with a fairly large drill (larger than 5/16 or so) the web is basically rubbing which creates the heat. By starting with a smaller drill (3/32 - 1/8) will greatly reduce the heat when you get up to the larger drill. This will help out a bunch.

Or, running the drill a slower speed and using a "oil" based cutting fluid will get you the results you are looking for.

[Herb]

Yep, that's it. I was using a 3/4'' hole saw in my drill press to drill 5 holes through some 3/8's angle iron. The first 5 holes took 3-4 minutes each using 30w oil. On the second piece of angle iron I ran out of oil after the second hole, so I grabbed some Castrol full synthetic 5-40- BIG mistake. Each of the remaining holes took 18- 20 minutes to do, just about killing my arm in the process. I learned two valuable lessons from that, 1- never use a synthetic oil as a cutting fluid, 2- I've always heard synthetics provided superior lubricating properties in automobile engines and I will never, ever use anything but in ANY of my car or tractor engines again.;)

[Sticky]

I start with a small hole and use my used motor oil. Slower speed, just the right pressure then move to the larger size. No probs.

[autoclassicnut]

Some great ideas ...And funny results on some of them....

[russlaferrera]

I used to get a cutting liquid from the local machine shop that they used in their drill presses and band saws. It was not oily and you mixed it 50-1 with water. I think it really was a rust inhibitor and the water was doing all the work.

It's water soluble oil. The same as water pump lubricant. If is sits long enough, it becomes rancid.

[nissan_crawler]

I've always used my used motor oil. I've ran a 7/8" hole saw through 3/4" plate 20 times, and it cut just as well the last one as it did the first.

I'm going to switch to a mist cooling setup, due to the oil mess, though.

[Deltarat]

I think the speed has alot to do with the cutting. I had a 100 year old hand operated drill press in the back of my shop. I converted it to electric 3/4 hp motor and large driven pulley on the press. I could drill an 1 1/4 hole through 1" steel without a pilot hole and with the oil I got from the machine shop. That is if I had someone strong enough to hold the iron if the bit grabbed. It would roll out those long curls of iron 6-8" long.

[Hip2u77]

Speaking of cutting fluids. . .

bohica2xo posted this on autoacforum.com at the end of his "PAG Olis - Do I need DEC" FAQ post.

"If you have an open bottle of old PAG laying about, mix it with water 6:1, and use it for cutting oil in the shop. That is still the major industrial use for PAG, as a water mixed machine tool coolant & lubricant. It works great in a pump sprayer ar the drill press..."