drilling holes

[dan_d]

Hi,
Until now i've been relying on the father-in-law's machine for emergency use, but I recently scored myself a old AirCo AC225 welder from an auction for $25, so i can finally start some "real" work Anyways, I was trying to drill a hole thru some angle iron that i picked up a while back and pretty much demolished an entire set of drill bits trying to get a 3/8" hole drilled! And this is even after I had poked a starter hole thru with some 6013@200A (didn't have any 6011 at the time)! Is there something better than titanium-coated bits from the local hardware store? They worked pretty well on the old steel frame i was fixing up (neighbour's *really* old field roller) but when i tried to drill the new stuff I welded on I wasted a good 30min on that one hole!:confused2:

As much as i'd love a torch, i doubt one is in the budget for this year, i've already got about 4 other major projects lined up... tho I did see a tiny kit with the benzomatic red & yellow cans for like $75 one time, dunno if it would do any better or not?

Thanks for any tips!
Dan

P.S: Here's the kit... looks like it may not be strong enough for my needs?
http://www.bernzomatic.com/PRODUCTS...etail/mid/1147/xmid/6954/xmfid/3/Default.aspx

 

[yomax4]

Sorry, the Bernzomatic mini set is wayyy expensive to run. You pay about as much for the gas as you would for 10 times bigger bottles. Also, the Torch is a Toy. Save up and get a real torch set. Also, Hardened steel like bed frames and what you are working with are hard on drill bits. I have had some luck in the past with a die grinder and a carbide burr after getting a pilot hole done. . I now have Plasma, Torch, Saws etc. So I am lucky to not be dealing with that hard material. Good luck..

 

[sal64]

hello first tit coated is only needed for highspeed drilling or milling i have been a machinist 27 years never needed or used tit coated, they look good so homeowners buy them. this is a good set at msc ind supplie, also sharping a drill right is important.

Order Qty of 1 = (1) 29 Piece Set
Price: $146.86 ea
In stock: 54
Mfr: Precision Twist Drill
Mfr #: 090162

Description: Sets - Drills Type: Jobber Size Range: 1/16-1/2x64ths
Type: Jobber
Size Range: 1/16-1/2x64ths
Fractional Size: 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 15/64, 1/4, 17/64, 9/32, 19/64, 5/16, 21/64, 11/32, 23/64, 3/8, 25/64, 13/32, 27/64, 7/16, 29/64, 15/32, 31/64, 1/2
Material: HSS
Finish/Coating: Bright
Number of Pieces: 29
Drill Grade: General Purpose
Point Angleｰ: 118

 

[lostcause]

it has been my experience that if you have to drill holes, it is cheaper and faster to buy new angle and not ruin drill bits, as opposed to free bed frames with frustration and dull, blue drill bits.

 

[Egon]

Maybe a set of better quality bits and some cutting oil!:thumbsup:

 

[CurlyDave]

Cobalt drill bits cost more than the usual ones, but last longer.

 

[Mark @ Everlast]

Over speeding your bit might cause the problem. It took me a while to figure out the bigger the bit, the slower I needed to go. Now, I only break one here or there from my impatience.

 

[MossRoad]

I always start with a pilot hole of, say 1/16" in really hard stuff. Then I move up progressively to the final size.

 

[BrentD]

It's also possible that poking the hole with the welder might have done something to the metal's temper that made it harder to drill.

 

[Scooby074]

It's also possible that poking the hole with the welder might have done something to the metal's temper that made it harder to drill.

:thumbsup:

temper or entrapped slag. plus the jagged edge of the burned hole will kill bits. especially cheap offshore ones.

good bits + oil and proper speed =

 

[tubewelder87]

i would say that everybody on here has the right idea. but it think that the main problem with your situation was the hole you made with the welder. Really what you did by doing that was make a harden piece inside of that piece of steel. it is called martinsite. It makes a very hard peice of steel bc of the way you heat it so quickly with the welding rod. I have a very cheap set of drill bits and always drill all of my holes. I think that unless you are real good it is hard to blow a accurate hole. with the cheapos you will have to sharpen more often and if you dont know how that can cause some real problems to. You can ruin a good bit just as fast as cheap one if you over heat it!! just my two cents worth!

 

[jayste]

While bed frame material is hard on drill bits my guess is that your method of making a pilot hole is your problem as well. I'm going to say that no pilot hole is better that one made with a welding rod. Making hard material even harder is a problem but the fact that the pilot hole you're making is not round as is an issue as well. A pilot hole also needs to be concentric with what you're using to follow it up with. A drill bit should make a round hole so start with a round hole. You're probably chipping away you're cutting edge on your drill bit due to the pilot hole. Like others have mentioned, good quality high speed drills are what most folks will need and cutting oil and the right RPM's will help. As Dave said you might have to step up to cobalt simply because you're drilling into some hard material but skip the pilot hole if you do. Let us know how it goes.:thumbsup:

 

[FarmerGene]

It's also possible that poking the hole with the welder might have done something to the metal's temper that made it harder to drill.

When you burn through a peice of metal the heat will work harden the steel and make it harder to drill.

 

[dan_d]

Thanks folks,
It didn't occur to me that the pilot 'hole' might have been the source of my troubles... I'll test out a non-welded peice tonight to see how that goes... assuming i can find a non-worn out bit!

As for the drillbit speed, how do I know what is fast/slow enough for the bit & material? is there some guidelines somewhere on where to start?

I didn't have any oil but I did use WD40, which seemed to help just a wee tiny bit, but i'll keep an eye out for the proper stuff

sal64, found the bits on that site, thanks! what's the difference between "Bright" finish on the ones you mention and these ones (MSC Item Detail) with a "surface treated" finish?


Thanks again for all the advice!
Dan

 

[flusher]

Thanks folks,
It didn't occur to me that the pilot 'hole' might have been the source of my troubles... I'll test out a non-welded peice tonight to see how that goes... assuming i can find a non-worn out bit!

As for the drillbit speed, how do I know what is fast/slow enough for the bit & material? is there some guidelines somewhere on where to start?

I didn't have any oil but I did use WD40, which seemed to help just a wee tiny bit, but i'll keep an eye out for the proper stuff

sal64, found the bits on that site, thanks! what's the difference between "Bright" finish on the ones you mention and these ones (MSC Item Detail) with a "surface treated" finish?


Thanks again for all the advice!
Dan

WD-40? Not the preferred fluid for your job.

Go the the plumbing dept at Home Depot or Lowe's and get a quart of cutting oil that is used for pipe threading. It works fine with twist drills.

 

[dan_d]

WD-40? Not the preferred fluid for your job.

Go the the plumbing dept at Home Depot or Lowe's and get a quart of cutting oil that is used for pipe threading. It works fine with twist drills.

Sounds like a plan. Thanks! :thumbsup:

 

[Brad_Blazer]

One more tip when you are drilling steel you need enough pressure on the bit to continually produce chips or better yet a continuous curl of shaved metal. If the pressure is too low or the speed is too high and the bit just rubs on the bottom of the hole the bit will instantly dull itself.

 

[easygo]

Also if you are using a hand held drill instead of a drill press ease the pressure as it gets through the material. (I need a drill press.) Especially as the bit diameter increases. Otherwise it might break through some and gets caught on the material that has not been drilled away yet. It is an excellent way to create holes that are just about impossible to finish without breaking the bit. I'm a master at that. I mean breaking large bits just as they punch through.
Any advice on that?

 

[dan_d]

hmmm... yeah i guess i was definitely going too fast then! :confused3:

live and learn i guess!

 

[jayste]

As for the drillbit speed, how do I know what is fast/slow enough for the bit & material? is there some guidelines somewhere on where to start?

I didn't have any oil but I did use WD40, which seemed to help just a wee tiny bit, but i'll keep an eye out for the proper stuff

Dan, unfortunately there's not a real good way to tell you about feed and speed on your hand drill. When I do it with a hand drill it's kind of by feel. Remember that smaller bits need faster speed and larger bits need slower. As far as feed (pressure or push) goes push it hard enough to get a short chip and not a "stringer" chip. As others have mentioned, you might want to get some cutting oil instead of WD-40. Let us know how it goes.:thumbsup: