I need to make a rectangular cutout

[BigRed2]

I need to make a rectangular cutout 10.3" x 13.8" in a 10 ga. mild steel plate. Does anyone know the best way to do this (other than "burning" it out)?
I was told that I could use a high speed circular saw w/ a "diamond" (??) blade.
Any suggestions would be helpful.

 

[IFRs]

plasma cut, water jet, oxy-acetylene, drill corner holes and cut the rest with a saw. I'd stay away from a circular saw with a special blade for safety reasons.

 

[theothercarl]

Drill your corners and use a jigsaw or a nibbler, circular saws can be used but tend to bind and some of the blades tend to blow apart under stress.

 

[JimMetalsCeramics]

Abrasive waterjet.

 

[BigRed2]

Thank you all for your help. Just today I asked a representative of DeWalt (Tools) if I could use some sort of saw; they recommended a circular saw with a high torgue motor and carbide blade. It would work best if I used low RPMs. The blade looked like it was made of the same material as a chop saw blade. IFRs, theothecarl, do you think that this would bind or blow apart?

 

[JimMetalsCeramics]

You will get chips flying EVERYWHERE. Use waterjet or a nibbler.

 

[funnelguy]

I have done the circular saw thing on aluminum. JimMetalsCeramics is right. I would not begin to try to make a cutout using this method.

How many parts are you talking about here? You could always mill out the cutout on a knee mill and dress up the corners with a file?

A laser's finish on material this thin wouldn't be any worse than the mauling the circular saw will administer.

Just a thought... have the DeWalt rep demonstrate the proper method for you.

 

[NickE]

Drill -- Scroll saw w/ 32tooth blade

Alternately use the sawzall.....

nick

Nick
I love materials science!

 

[GRoberts]

They do have low RPM cold saws for metal out there. Haven't tried them on steel, but the carbide blades have always worked well on aluminum. It is true that chips get everywhere, just like sawdust, but a broom takes care of that nicely. If I just had a few to do though, I would go with NickE's advice and use a sawsall. They can cut gage thickness metal fairly quickly.

 

[funnelguy]

Again, I wouldn't try the carbide circular saw on steel. Cold saws are one thing, freehand plunge cuts into relatively thin steel are another animal altogether. I think you will destroy the blade fairly quickly. I cannot imagine how a diamond blade would work on steel.

I have cut a fair amount of .125 and .187" aluminum with a circular saw with a carbide tipped blade. You would need some light lube, and a sand blaster's hood would help to keep those hot chips off the back of your neck! A few of them will probably stick to the ceiling.

Please don't try the circular saw route.
Or... maybe I'm wrong. But I doubt it.

 

[mediaids]

i have done this type of rectangular cutouts by two different methods.
1.make holes at the corners with a round punch on power
press.then cut awy with a jigsaw using carbide blade with
about 22 teeths.
2.for greater accuracy,speed and repeatabilty,get it done on a cnc laser cutting machine.