Can I use hole saw for 1.125" hole in 3/4" steel plate?

[LewisCobb]

Hi -
Never having done this before I figured I'd ask the question here to see if I am barking up the wrong tree.

I have a 3/4" thick plate of steel and I want to cut a few holes in it - I don't have anything to do this with, but I can borrow a mag drill for a short time. There's a chuck attachment for the drill, and I am wondering if a hole saw would work to cut a 1-1/8" diameter hole if I was to proceed slowly using cutting oil and clear the chips often. And if this is possible, what type of hole saw - brand/material, should I be looking at ?

Thanks !

[Country Metals]

If you can get a mag drill, why don't you just buy a 1 1/8" bit for it? It will save you a lot of asprin. Hole Saws are not really designed to drill steel. I have certain carbide tooth ones for drilling S/S sheet, but I rely on my hougan for my holes.

Even though a hole saw says it drills wood and steel, it really means that yes it can do it but it really can't.

[Sandy]

That hole saw will be a real wrestling match. Hard way to go. As long as you can get the mag drill, as mentioned, getting an annular cutter to do the job is the way to go. If not take it in and have someone drill the holes for you.

[ja baudin]

I've drilled several 1 1/8 holes in some 5/16ths plate steel for a bar b que grill project before. It takes time and wears on you nerves a little but can be done.

[MMW]

If you have a mag drill that fits an annular cutter than that is the way to go. If it is just set up with a drill chuck use drill bits. Drill a 1/4" pilot hole then use the 1.125" drill but with lots of coolant & it will be fine. Forget the hole saw.

If you have to buy a 1.125" drill bit get the one with a three side flatted shank. That way it doesn't spin in the chuck.

[walker]

I recently cut about 20 2" holes in 1/2" steel with a hole saw. Only one hole saw was needed. The keys are speed reduction, and chip removal. Some of the guy I talk with will drill a 1/4"ish hole at the edge of where the hle saw cuts,allowing the chios to fall out. I just set up an air nozzle with pointing at teh saw on low and i did the job for me. Speed for my saw was 70rpm. I used my milling machine to get that low of speed, as my drill press would only go down to 125rpm. Not sure what rpm the mag drill goes down to, hopefully it will go slow enough. The hole saw manf should list rpm for your size cutting into steel, follow it and you will be happy.

[tanglediver]

Bi-Metal Hole Saws

Hole saws will work as long as they are Bi-Metal saws. I agree, you need to slow down and use lots of oil. Keep light, even pressure. As long as the saw keeps turning and making chips, you're doin' fine.

[MMW]

A mag drill is usually to fast for a hole saw.

[LewisCobb]

Hi folks -
Thanks for all the good feedback. It seems I may be better served getting the proper bit for the magdrill - but I am going to have to go on a "begging" mission for it - I can't justify the cost of one for just 2 holes.

Appreciate the feedback - thanks again.

[Bistineau]

2 Holes?

If all you need are 2 holes, call a local machine shop for a price. Just a thought. Might be cheaper than a hole saw, dunno fer shure.

[johnboy1845]

is the 3/4" plate carbon? if so and you only have 2 holes to drill get a 1/2" drill, if you dont have a drill press/mill or are unable to position it in one. the mag drill is way to fast for a hole saw.

[LewisCobb]

is the 3/4" plate carbon? if so and you only have 2 holes to drill get a 1/2" drill, if you dont have a drill press/mill or are unable to position it in one. the mag drill is way to fast for a hole saw.

I'm pretty sure the plate is carbon - it's a freebee that I got from a buddy that I am hoping to make a little welding table out of - it's 2'x4' so it's not exactly light, and somewhat overkill for strictly tig work, but hey, it was free

Taking it to a machine shop sounds easy enough but I can't get it in the back of my VW Golf, and the buddy that gave it to me lives in another city. He dropped this thing off about 2 months ago and I am sure he was laughing thinking about how I am going to wrestle this thing around the garage....

The 1/2" hand drill and stepping up in size bits might be an option - I have a place where another friend works that I could go to and bum the bits needed.

[1930case]

What particular purpose do the holes serve and is there a lower-effort way to do what you want?

[LewisCobb]

What particular purpose do the holes serve and is there a lower-effort way to do what you want?

Just realized that I never explained the "holes".

There are a couple of smaller ugly holes in the plate at the moment - more like failed attempts with a plasma cutter - and I was thinking about opening them up to a "clean" hole and then plugging them with a little rod, and then grind off the surface smooth again. But the more I think about this the more I just may leave them there and use the ratty holes that are there for receptacles for some home made clamps. In any case, I am going to use the plate as is once I get the legs made for it, and see what evolves from the type of work I will tend to do on it.

I'm sketching up some concepts for the table at the moment and will post up a 'jpg for some critiques when it's done.

I'm fairly new to all this and seeing as it's hobby stuff, I probably tend to over-worry and over-think things. it's great to have a resource like this forum to bounce questions off the experts, or people that have more experience than me...

I've been fiddling with learning tig welding for about 2 years off and on - in between "life" getting in the way. Up to now I have used some saw horses and plywood with a small piece of sheet metal. It`s worked for the small number of things that I have built and practiced with, but the stench of burning wood is wearing thin on me, and when I was offered this plate of steel delivered to my door for free, I jumped at it !

[Diddle]

forget about

There's no way I would drill em out just to plug weld.