Help with metal drilling

[ronjhall]

It has already be said. But here goes. Slow the drill down. After you have dulled a drill in a bed rail. Metal will become hard from the heat. Heat red hot with a torch. Then let cool slowly.

 

[ArkLaTexSam]

I wish I had thought about using a cooling oil when I drilled my bucket for a toothbar. I went super crawl speed slow until I got the holes started with a hand drill. I managed to not tear up my drill bit because going slow keeps the heat down. Sure did make some noise!!!!!!!!!!!!!!!!!!

ArkLaTexSam

 

[txslowpoke]

They also have a cutting "crayon" or paste stick out. Basically it looks like a big crayon, you hit the bit with it as you are drilling, or cover bit prior to drilling. Its very clean, one person user friendly vs the cuttin oil.

 

[Mcfly89]

we use a cutting fluid called mystic metal mover. it is the best product i have ever used and would highly recommend it for drilling anything (except aluminum of course, in which case we use alumicut). the crayon product sounds interesting too. another tip that noone has mentioned...the drill doctor ONLY works on non-split point bits...regardless of what the packaging says. it does a wonderful job of sharpening standard drill bits tho. split point bits are by far the easiest starting and best bits out there. personally i wouldnt own anything else...on purpose.

on a side note, if you have to get your metal red hot to anneal it and dont have a set of torches, you could keep using your dull drill bit on high speed, hehe

 

[Deerlope]

we use a cutting fluid called mystic metal mover. it is the best product i have ever used and would highly recommend it for drilling anything (except aluminum of course, in which case we use alumicut). the crayon product sounds interesting too. another tip that noone has mentioned...the drill doctor ONLY works on non-split point bits...regardless of what the packaging says. it does a wonderful job of sharpening standard drill bits tho. split point bits are by far the easiest starting and best bits out there. personally i wouldnt own anything else...on purpose.

on a side note, if you have to get your metal red hot to anneal it and dont have a set of torches, you could keep using your dull drill bit on high speed, hehe

I have a drill doc and have found a way to sharpen the split piont bits in it. I just need to get the corser stone for my bits over 1/2 dia.

 

[patrick_g]

Larry, OK, Most things are relative, shades of grey not black or white. Motor oil is better than ambient air for cooling a drill bit. Now if you blew enough compressed air on the tip of the bit, I'm not sure that motor oil would be superior to it. As I sad in a previous pose and as Eddie said... WATER is good way to cool the bit.

Notice how I keep saying COOLING and not lubrication? Heat is the enemy of the sharp parts of the bit. Overheating a bit dulls it way faster than just the metal you are removing. A drill bit is just a rotating chisel with a fixed angle of atack. Would you take a torch to a good sharp chisel? Of course not as the heat would be a BAD thing.

Of course cutting oil is THE Right Stuff as it is especially for the purpose and most other it-sorta-works-ok substitutes are not typically as good (no big surprise.) My nose would grow if I claimed to have never used motor oil in liew of cutting oil. It was handy and way better than the ever present air. I have also used ATF and find it way better than motor oil. Note the earlier post about an experienced machinist using ATF and cutting oil mix.

My MOTOR OIL is counter productive comment stands, in this context... it is counter productive to replace a better fluid for the purpose with motor oil. Of all the available typical fluids that people frequently use as a substitute for REAL CUTTING OIL (fluid) motor oil is probably the poorest, hence my comment that its use is counter productive as any other commonly used fluid, including water, would be better. If you took my comment to mean I claim motor oil to be worse than nothing but ambient air then, sorry, not the way I meant it.

I doubt that a black hummer filled with shock troops from SAE or any such organization will descend en masse on your loacation when someone tips them off about your using motor oil for cutting oil. Who knows... maybe used motor oil would be better, especially if the lubricity had been reduced and you decant it gently to avoid the sludge and wear particles that settle out.

Pat

 

[Egon]

After the drill bit gets hot it may not be the same drill bit you stated out with. Even after it cools down and is resharpened.

 

[BTDT]

They also have a cutting "crayon" or paste stick out. Basically it looks like a big crayon, you hit the bit with it as you are drilling, or cover bit prior to drilling. Its very clean, one person user friendly vs the cuttin oil.

We used to use this when I was an iron-worker by trade. We had a tube that was about the size of a tube of grease. It is more like a stick of wax. We would just shove the bit into it and drill. As bit got hot, wax/grease would melt and keep bit lubricated. It was also good because it cooled fairly quickly and trapped the metal shavings. Didn't have oil spots, puddles, all over the place, nice when your working above ground (sky scrapers).

Grainger sells several different types, (cutting oil, creams, stick, sprays, etc)

 

[patrick_g]

Do they come in designer colors and a choice of scents?

Pat

 

[rutwad]

I can remember once trying to drill through a leaf spring. I was using my dad's drillpress and "tap magic" oil. It obviously still got hot due to the smoke and terrible fumes left from the steamed oil! Never did get that leaf spring hole drilled either.

 

[patrick_g]

Yesterday I was drilling a hole in my pallet forks 6 inches or so from the tip so I could put a bolt in to keep a chain from slipping off when I use a bridle to lift 55 gal drums of corn gluten (cattle feed.) I guess that overall I improved the quality of my drill bit collection as I removed two of them from use by breaking them in half.

I used CRC brand spray can cutting oil that gives a clinging foam that turns liquid fairly soon. I successfully drilled a small pilot hole and then broke a bit of about 1/4 inch and then another at 3/8-7/16 range. I credit two causes. CHEAP GOLD COLORED BITS FROM CHINA and a REAL DRILL, a Milwaukee 3/8 corded Magnum Hole Shooter that has so much torque it will twist your wrist if a bit jams. Funny about those cheap gold colored Chinese bits from HF or a traveling tool show (Cummins, I think), some of them are really darned good and others that look the same are caca de vaca, and bend or snap way too easily and would only last if they were used in wood.

At first I thought it was an accident or just a flawed bit but now I have decided once you snap a couple bits in an index that they are probably all the "BAD" ones and should be reserved for wood. For what it is worth I have had much beter luck with the HF bits than the traveling tool show ones.

The second rung of the ladder is twice as high as the first and that is how I rank much of the HF bits and such, twice as good, at least, as some of the REAL JUNK but not near the top of the ladder.

Someone mentioned Vermont bits. Marketed under a real YANKEE name but they are from South Carolina. I have some and they are good stuff. They make pretty good masonry bits too.

Pat

 

[Deerlope]

I remember a few ago that I went to a friends home to help him with a truck project. It involved drilling a few hole for some pop rivets. When I got there he had already started and he said that the metal was really hard. That he had broken 2 drills bits and that he was on his 3rd one and asked if I could go get him some more. Which I was willing to do but I wanted to try drill one myself. I found that he had been running the drill in REVERSE!!!!!!!!!!!!!!!!!!!!!!! he managed to literly burn one hole thru.

 

[scott_vt]

I successfully drilled a small pilot hole and then broke a bit of about 1/4 inch and then another at 3/8-7/16 range. I credit two causes. CHEAP GOLD COLORED BITS FROM CHINA

Someone mentioned Vermont bits. Marketed under a real YANKEE name but they are from South Carolina. I have some and they are good stuff. They make pretty good masonry bits too.

Pat

Amen Pat,
The cheap gold colored bits from china are garbage !

In our modelshop we use PTD Precision Twist Drill Co bits. Plain old HSS drill bits, no coating, and they can be readily resharpened. If you need something to go through a harder material then we use a carbide bit.

 

[patrick_g]

Aye Scotty and so thrifty man, thrifty. Actually I have some gold colored cheap Chinese bits that are just fine, surprisingly. The trick is that I can't tell by looking at the store which is which. That is why if I break or bend a couple from an index then that index is relegated to wood. Before I instituted that policy I broke a large percentage of the junk ones.

I have some of the good ones that have cut a lot of metal, a surprising amount of metal before getting dull. I have a bit sharpener now and find that it takes some skill and practice to get a good edge but I am hopeful that it will be within my abiltities to master. I don't have the skill and ability to sharpen a bit at a bench grinder I can grind it but whether or not it gets sharpened is a different matter.

Quite a chuckle about the truck project and the attempt to drill backwards. Haven't we all at least accidently tried at one time or another? The criticism I used to get of my hand drilling style was that I really didn't need to pull the trigger since I pushed so hard I was just punching holes not drilling them. Now I try to modulate the speed and pressure while observing the shavings and it helps.

Pat

 

[PBinWA]

One point that no one has mentioned.

Cutting oil is typically found in the plumbing section of most real hardware stores. Look for the stacks of black pipe and you will find cutting oil near by.

It's cheap and readily available. I know when I first heard of it I thought I was looking for something special and had no idea it was a common thing.

PB

 

[txslowpoke]

My wife preferrs I use the pink cutting paste in the Drakkar scent Masks the sweat scent nicely, so she says
The paste I used came in a package about the size of a permanent marker, coat the bit tip and go to work, recoat it as needed.

 

[patrick_g]

Tex, Thanks for the info, I would like to try some of the paste. I'd think it would be more economical than the spray can of foam cutting fluid and easier to keep where you need it.

How easy does it liquify and does it run all over or stay pretty much where you need it?

About scents.. I bought a trailer load of empty 55 gal plastic drums to make troughs out of, store feed, and such projects. I was interested/concerned about what they had held. Most were scents, such as eau de rainforest and such. I suppose once rinsed out and left in the sun a while the cattle will not be put off by the residual rainforest smell, or the cherry, or whatever.

Pat

 

[scott_vt]

Afternoon Pat,
This is what I do with my plastic 55 gal drums ! I cut a semicircle out on one end and fill it with sand for my driveway. I bought some from a local dairy chemical supplier. Cheap Oh yeah I built a stand so as not to bend over too much

 

[Berniep]

My drill doctor absolutely will sharpen split point bits it will even make split point bits out of regular bits. It has to be a model that has the extra port on the side for split point bits. Contrary to another poster it is not idiot proof as this idiot (me) couldn't get a good edge on a bit at first. It took an experienced operator to show me the proper technique. After that I now have bits that actually cut metal.
I didn't see it mentioned but maybe it was, Almost all drill presses sold at home stores and such are woodworking drill presses and are much too high speed for proper metal working even at the lowest setting. I saw one that was called a "Metal Worker" that the lowest speed was something like 600 rpm. You really should get down below 200 for larger bits, ie 1/2" or larger.
Will they work? Sure but slower is better. Once you see an Ellis drill press turning an7/8 inch bit at about 100 rpm through a half inch steel plate and making those real long shavings you will want a real drill press.

 

[TrippleT]

On most projects I have done, I have found if your press runs to fast do not put as much pressure on the bit. I just let nature take it's course.