Drilling 2" holes in 3/16" Plate what can I use/ bi-metals or ?

[mofoco1]

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I need to get 7 - 2" holes drilled into my 3/16" skidPlate. What is the easiest way to do it at home. I have a few hole saws that I have used to cut holes in hoods and hood scoops, but never on something this thick. The machine shop wants a left testicle to punch them out....Mo

 

[Viperwolf1]

If its aluminum I would use a hole saw. If its steel you might consider a jig saw.

 

[Rickb1b]

I've used a whole saw an 1/4 in steel. Make sure to use a hole saw made for steel, take slow and keep it cool.

 

[KyleQ]

A hole saw in a drill press with plenty of oil will work, but you have to go slow.

Your other option is to have the holes torched out and then clean them up with a burr. Torch them smaller than what you want - create a circle around the torched opening and use a carbide burr to finish it off.

Your other option is a jig saw, but drill as many holes as you can stand in a circular pattern and go to town..

 

[Rickb1b]

Also drill half way through then flip it over to finish.

 

[bmc69]

Plasma torch with a hole template...

 

[Timmy390]

Plasma torch with a hole template...

X2 on this if you have a plasma cutter

As stated, if using a hole saw, make sure it's for metal of you will not get far at all.

I seen where Lowe's had a new version of hole saw......it has "grit" and not teeth. Kind of grinds it's way through. Think it was for metal.

Tim

 

[KyleQ]

Plasma torch with a hole template...

I dot his all of the time - cardboard works, but it does smoke. Wood is perfect though!

 

[jim3326]

I used a hole saw on 3/8" stainless (actually several saws but I had a bunch of holes to drill too) steel. Each saw would cut about 3-4 holes before bitting the dust. I had a mill so it wasn't that hard but there is a trick to make it easier. Start with just scoring the metal with the saw so you can see where it's going to cut, then drill two 1/8" or 3/16" holes in the cutting track on opposite sides, then start cutting on the lowest speed you can and use a good cutting fluid or lots of oil. The holes keep the saw cleaned out and help it take a good bite. I also had wood under it to support it when it went through.

Jim W.

 

[jim3326]

I seen where Lowe's had a new version of hole saw......it has "grit" and not teeth. Kind of grinds it's way through. Think it was for metal.

Tim

I think that one is for masonry or stone work. I used one of those on a stone tile countertop.

Jim W.

 

[Rustytruck]

Since I dont have a plasma like you, I would use a holesaw with a lenox blade running in a 1/2 chuck turning pretty slow, You have to keep a steady pressure as it cuts. You must grind off any rust before you start. Rust scale will wipe out the cutting teeth. Steel has a tough skin on top so what I would do is while your cutter is at its sharpest start one hole and cut down about 1/4 of the thickness your going through then flip the plate and do the same on the other side. now move to the next hole and do the same. once you get all your holes started then come back and finish cutting through the holes. That way your sharpest teeth are cutting through the hardest part of the steel. If your using Aluminium you should get through this with one cutter.
If your using 1010-1018 cold roll steel then you may get it done with one cutter but may need 2. Dont use any hot roll steel or 4130 steel unless you are using a hot knife to cut the holes. Make sure you run coolant on the hole saw. I personally use ATF on projects like these. You will need alot of patience and will power not to over load the saw or run it too fast.
I get my holesaws from Mc Master carr.

Check our vendor forum at one time there was a person looking for work like this and could quote you one off stuff. He seemed very reasonable.

 

[jim3326]

You have to keep a steady pressure as it cuts. You must grind off any rust before you start. Rust scale will wipe out the cutting teeth. Steel has a tough skin on top so what I would do is while your cutter is at its sharpest start one hole and cut down about 1/4 of the thickness your going through then flip the plate and do the same on the other side.

X2 on the rust but if you grind off the mill scale instead of cut through it they will last longer.

Jim W.

 

[mofoco1]

The saws I have are Milwaukee's gonna give it a shot with them and the press. No convenient and or economical access to a plasma torch/table or a jigsaw unfortunately. Thanks..Will post when done...Mo

 

[xcntrk]

Perfect excuse to get a plasma cutter..

I would use a plasma torch with hole template - or better yet a radius guide for the plasma gun...

 

[DuctTape]

Plasma torch with a hole template...

Ya, I bet you'll drive yourself crazy trying to saw it. See how much a local machine shop would charge you.

 

[bmc69]

I also use my poor-man's plasma table a lot for the smaller stuff like that if the cut path is more complex than just a circle; I hang my 150A torch on a piece of PVC pipe clamped to the table of my CNC Bridgeport and cut stuff on a cutting table placed right next to it.

 

[bad 68]

When I hole saw through aluminum I lube with water not oil. If you need to do any welding on aluminum don't use oil.

The Milwaukee bits should get a lot of holes in mild steel before giving it up.

 

[67 roller]

If you don't have a plasma cutter , try what jim3326 said it actually helps more than you would think .

 

[suckerpunched]

Mo, milwaukee's should work fine. The key is lots of oil and slow rpm on the drill. I have cut 1" steel with a hole saw. The bigger diameter the slower it needs to turn. A hand drill is difficult but it might work, or it might rip your arm off. If you have trouble and need a big ass drill press PM me, I am in dinuba, can help you this weekend.

 

[mofoco1]

Thanks SP, I will bear your offer in mind. I went by my in laws where I keep my metal, and it will have to wait for another day. The pieces I had were either too small or ear marked for other projects, will get me a piece Friday on the way home after work.