Cutting 5/8-3/4" thick steel

[bagged89s10]

I have a 5/8" and a 3/4" thick steel plate I'm going to be cutting to build a vise stand. Both plates are going to have a few curves in them.

My plasma cutter is a hypertherm 380 but it's only rated to cut 3/8" thick steel. I've only ever cut 1/4" with it. Can I gouge out half way thru and then go over it again to get the full cut? I'm not too worried about having to grind the cut smooth afterwards.

Or am I better off using a jig saw with the correct metal blades to cut it. Here is a cardboard template of the design for the 5/8" plate. It's about 17" x 16".

 

[Ruger_556]

Acetylene torch if you have one and a steady hand. Jigsaw isn't going to do it...

 

[turbowoodworker]

torch.

 

[Brian_WK]

cut it twice into 5/16-3/8 with plasma and then bolt them together and clean the edges with a grinder?

Brian

 

[APEowner]

Your plasma plan will work just fine. The cuts will be ugly and you'll get significant blow back but it'll work.

 

[bagged89s10]

cut it twice into 5/16-3/8 with plasma and then bolt them together and clean the edges with a grinder?

Brian

Yeah I think that might be the easiest and fastest since I don't have a torch.

 

[Superbec]

Your plasma plan will work just fine. The cuts will be ugly and you'll get significant blow back but it'll work.

he will destroy a bunch of consumables maybe the torch and the result will be a very hard to grind ugly thing .... if he will ever sever 3/4 .

don't ask how I know

angle grinder, cut-off discs , some patience .

 

[bagged89s10]

he will destroy a bunch of consumables maybe the torch and the result will be a very hard to grind ugly thing .... if he will ever sever 3/4 .



don't ask how I know



angle grinder, cut-off discs , some patience .

Last thing I want to do is destroy my plasma cutter. I could just go with an angle grinder and cut off disks if I have to. Come to think about it. This rusty steel I go for free just might make it more work for me than just grabbing a few clean pieces of 5/16 or 3/8 and welding them together.

 

[NASTYZEN]

Transfer your pattern to the plate. Ideally with a scriber and take it to your local welding shop. Should be no more than 20 bucks and it will save you a lot of grief. Thats a thick piece of metal you have there.

 

[paranoid56]

for that, just find somebody local to help you out. as i am all for DIY but something that thick, i would run away quick lol.

 

[Kevin54]

I would try to find someone around that either has a bandsaw that will handle that thickness, or find someone with a waterjet, and go that route. The time you spend on shaping that would better be spent on finding a source to do it to where it is nice and clean. Most job shops could knock it out for you for a reasonable price if you tell them what it is for, and let them know that you aren't some business looking to get something done.

 

[APEowner]

he will destroy a bunch of consumables maybe the torch and the result will be a very hard to grind ugly thing .... if he will ever sever 3/4 .

don't ask how I know

angle grinder, cut-off discs , some patience .

I don't have any experience with any of the Hypertherm units but I've done multi-pass cuts on thick stock with my Miller many times.

 

[rsanter]

that will be very slow going and hard to cut with the plasma and will be hard on the consumables
jig saw will be very slow going

options, or at least what I would do, in the order I would try them

1 find someone with a torch

2 drill a bunch of small holes around the perimeter of the shape you want. open the holes up to a little larger size to reduce the gap between them.
then....
you can now use the plasma to try to burn through each og the links between the holes starting the plasma torch at an angle.
or you can now use a jig saw/cut saw to go through the links between the holes.
or you can keep drilling bigger holes till you break through from hole to hole.

3 fine someone or buy a metal cutting skill saw. I bought mine for $80 on amazon. its not top og the line but has been very handy

bob

 

[-Brent-]

Novice plasma cutter user here but I was wondering what the blowback would be like since it's not cutting through all the material?

 

[ovrrdrive]

If you're wanting to do it yourself I'd say straighten out the curves and cut it with a cutoff wheel. You can always go back and pretty it up later on if you get a torch or a better plasma. There are several better ways to do it but they all require you to either buy new equipment or pay someone to do it that already has it. You're squarely in the middle of PM65 territory for plasma with that steel.

 

[ovrrdrive]

Novice plasma cutter user here but I was wondering what the blowback would be like since it's not cutting through all the material?

5000-10000 degree molten metal hurts when it comes into contact with your skin...

 

[willy (traer)]

I'm almost positive I've cut at least 1/2" with my old 380. Try it - you'll know pretty damn quick if its going to work. Hypertherm Plasma's always seem to be way under-rated on their cutting capacities.

 

[red92s]

I'd email a DXF to one of our suppliers and have it done on their laser table. I realize that's not terribly helpful, but that's what I'd do.

 

[-Brent-]

5000-10000 degree molten metal hurts when it comes into contact with your skin...

Ha! I get that but would it splatter back at you since it's not going through? Or is that an obvious reality? I've only plasma cut thin stuff, everything blew through.

 

[bagged89s10]

Cutting 5/8-3/4" thick steel

I stopped at the steel yard on my way home from work and found these two 1/4" thick 16" circle cutoffs. I'll be able to quickly plasma cut each one separately and stack and plug weld it together. 1/2" should be plenty thick and I will slightly alter my design to fit.

 

[BD1]

I like those circles. Maybe consider the circles as is and make some holes for a hammer or tool holder. It can be really handy plus the circles are neatly cut. I would leave them as is. They longer rear will add some hangover weight too.

 

[sberry]

Why would it need to be thick?

 

[Farmall450]

I like those circles. Maybe consider the circles as is and make some holes for a hammer or tool holder. It can be really handy plus the circles are neatly cut. I would leave them as is. They longer rear will add some hangover weight too.

^ This. No need to fix what isn't broke.

 

[rsanter]

I like those circles. Maybe consider the circles as is and make some holes for a hammer or tool holder. It can be really handy plus the circles are neatly cut. I would leave them as is. They longer rear will add some hangover weight too.

This is what I was thinking

Bob

 

[zkling]

FYI, stacking two 1/4" pieces will not give the same as one 1/2" piece. Go pay someone with a torch to cut a piece out of the 5/8" plate.

 

[sberry]

A vise should be on some kind of bench, needs someplace to sit tools and stuff one is working on.

 

[Griff93]

This is an easy job for someone with a CNC plasma table with a big enough unit to cut this material. We regularly cut up to 1" with ours. If you could create a dxf file of what you want it's really easy for someone to quote it. Something like that would probably be in the range of $30-50 including material.

Waterjet is a bad idea for this due to the cost. I have sent out a RFQ for stuff like this and it's been very expensive due to how slow water jet cuts. Our local place gets $165/hr for cutting.

 

[bagged89s10]

FYI, stacking two 1/4" pieces will not give the same as one 1/2" piece. Go pay someone with a torch to cut a piece out of the 5/8" plate.

I agree it won't give the same strength. If I was building something that had 1/2" steel specified for the project, I wouldn't deviate from using a 1/2" plate.

I think for this application, stacking and plug welding the plates will be fine. This plate is going to be mounted on an ibeam, and the part of the plate where the vise is mounted will be centered on the ibeam. The part of the plate that is larger than the vise mounting surface is mostly aesthetic.

 

[bagged89s10]

A vise should be on some kind of bench, needs someplace to sit tools and stuff one is working on.

I have 2 bench mounted vises already. There are certain times you need to work on something and be able to walk all around it.

 

[sberry]

I agree it doesn't need strength around it, the 1/4 will be absolutely fine,,, why stack them at all, save the other plate for something else.

 

[bagged89s10]

I agree it doesn't need strength around it, the 1/4 will be absolutely fine,,, why stack them at all, save the other plate for something else.

I'll be cutting a 3" hole or two or maybe a oval in the top plate to act like a little parts tray for small screws or bolts. Just want a small table area for little parts and keep them from rolling off and onto the floor.

 

[Woodman920]

Acetylene torch will be quickest and best. Run it down to a shop of you don't have one.

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[rustyjames]

Another vote for the oxy/ace, that's a piece of cake for that process.

 

[Teenager with old tools]

Cutting 5/8-3/4" thick steel

Double post


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[Teenager with old tools]

Cutting 5/8-3/4" thick steel

Buy a Cnc plasma cutter


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[Jzkudzin]

I have a 5/8" and a 3/4" thick steel plate I'm going to be cutting to build a vise stand. Both plates are going to have a few curves in them.

My plasma cutter is a hypertherm 380 but it's only rated to cut 3/8" thick steel. I've only ever cut 1/4" with it. Can I gouge out half way thru and then go over it again to get the full cut? I'm not too worried about having to grind the cut smooth afterwards.

Or am I better off using a jig saw with the correct metal blades to cut it. Here is a cardboard template of the design for the 5/8" plate. It's about 17" x 16".

You could take it to a tech school let a student get some torch practice make it big for error sake and make a donation to any welding or fabrication clubs they may have win win.

 

[BADSIX]

I worked for a small shipyard on the west coast and all the welders there used a cutting torch. they could cut 3/4 perfect, it would be so smooth you would have thought someone took a grinder to it.
Jay D.