Drilling (or burning) large holes???

[HCJtractor]

I have my new welder and am slowly setting up a shop for fabrication. Several projects I have in mind require large holes in steel plate (1/4 to 1/2").
Holes need to be up to 2 1/2" diameter. Generally, how do you guys make holes in steel? I have a good drill press, but never drilled anything larger than 3/4" I don't have a mag drill, or a plasma, or even a torch. What are reasonable limits with a drill press using bits or a hole saw? I know nothing about steel cutting hole saws. Any info would be helpful.

One project I have in mind needs a hole 2 1/2" but it does not need to be accurate or even round. So burning it seems the way to go. I have heard about gouging with a welder but know nothing about it. Is that possible? I have a Bobcat 250 and a little Everlast Powerarc 200.

 

[Spudland_Dave]

I've drilled 4" holes in 1/4" plate with some good Lenox BiMetal Holesaws. Nice accurate & clean holes.
Option 2 would be Plasma.

 

[Shield Arc]

I have a mill and a pretty good selection on roto broaches. Took a 3/4-inch R-8 adapter, and modified it to accept the roto broaches.
I also have a shop built rotating table, with a shop built circle burner. I can cut really accurate holes with it.

 

[Deere Dude]

Without spending a bunch of money I would buy a handful of 1/4 rods and put the wood to the welder. You should be able to cut through that in 5 or 10 minutes with a little playing. Once you get a small hole then just start working the edges. It would be cheaper than a hole saw or a mill. If you do it over a concrete floor all the droppings could pit the floor unless put a metal bucket under it to catch all the molten metal. I cut a lot of holes that way for 40 years, but always wish I had a torch. Oh well. Works for me. :thumbsup:

 

[Grayson Klassen]

Walter makes some really good carbide holesaws that are machine grade. They are expensive but will do the job in plate steel and not over stress your drill press. Torching holes even if you are good at it leaves grinding to be done and hard spots. Plasma is better but a decent machine for half inch is expensive.

 

[yomax4]

Rent a plasma for a couple of hours or a torch set or have a shop do the holes. Both will do a fine job and not cause a bunch of messing around.

 

[HCJtractor]

Without spending a bunch of money I would buy a handful of 1/4 rods and put the wood to the welder. You should be able to cut through that in 5 or 10 minutes with a little playing. Once you get a small hole then just start working the edges. It would be cheaper than a hole saw or a mill. If you do it over a concrete floor all the droppings could pit the floor unless put a metal bucket under it to catch all the molten metal. I cut a lot of holes that way for 40 years, but always wish I had a torch. Oh well. Works for me. :thumbsup:

I have wondered about that. I know they make gouging electrodes but don't know anything about that either. What you are saying is just use standard electrodes (say 6011??) and start burning? I should be good at that, as I have burned lots of holes (accidentally!) Seriously, you just start burning at a high amperage? Any precautions I should take other than the molten metal?

 

[HCJtractor]

I've drilled 4" holes in 1/4" plate with some good Lenox BiMetal Holesaws. Nice accurate & clean holes.
Option 2 would be Plasma.

Dave, I assume you do this on your drill press at low speed with lots of cutting oil?? Could I get through 1/2 plate?

 

[J_J]

Check out these products.

http://www.flangewizard.com/products118.html

Look at the videos.

 

[Army grunt]

I use hole saws with alot of cutting oil. Just turn slowly soas not to over heat the bits.1/4 to 1/2 are easy to drill with good grade drills, just step up to 1/2 " using a 1/4 then 3/8 then 1/2 , also using plenty of oil.
Army Grunt