Best way to cut sheetmetal

Ross/Kzoo

Ross/Kzoo

Well-known member
I've got a couple of projects coming up and need to some 18 and/or 20 gauge sheet metal into strips. Some will be 2" wide and some about 4" wide. The lengths will vary from 18" to about 4'. What will be the best way to accomplish this? I have a woodworking band saw. Would getting a metal cutting blade do the job. It's too thick for hand metal snips. Maybe but a pneumatic or electric shear? Wha would you suggest?
 
Use what you have. Don't over-complicate your work. It is easy to get sucked into feeling we need a new tool for every specialty task.
 
Aviation snips cut 18 and 20 gauge, it's tough but doable. I cut 16 gauge with my snips. If you want a nice edge bring the metal to a sheetmetal shop and within seconds you will have a perfect cut.
 
Wood band saws have way too fast a cutting speed unless you can really slow down the speed. I think wood band saws go 10 times faster.

How flat do the pieces need to be? Cutting lots of pieces by hand would be hurt and cause lots of bending.

I did my first cutting with a saber saw. The key is to get a blade with a blade pitch tighter then the thickness of the metal or close to it. The more teeth per inch the less tearing you get and the cleaner the line.

Later I got a power shear at a garage sale REAL cheap. Some distortion at the edge, but nice to use.

Sometimes I use my Sawsall, but that usually causes more distortion unless you can keep it tight to the material.

That is my experience hope it helps.
 
There are several sheet metal/ductwork shops in the Kalamazoo area. Make up a cut/size list, have them cut it all up in a shear. No big burrs, very accurate. Will you be at Gilmore tomorrow?
 
MikeK said:
There are several sheet metal/ductwork shops in the Kalamazoo area. Make up a cut/size list, have them cut it all up in a shear. No big burrs, very accurate. Will you be at Gilmore tomorrow?
Click to expand...

Thanks, no I have a prior commitment so I can't make it. I really wish I could.
 
I do agree with the metal shop doing the cutting, but I've had to get things done with no time to pack up and travel, so I mark the line, clamp piece safely to a bench, then use my angle grinder with a good cutting wheel and cut close to my line, then use grinder to bring it down to my line usually with a piece of straight-edge strap steel also clamped onto my line to see where I'm going and not go beyond my line. About 8 to 10 minute procedure for a 3 foot or so cut. Hand file & sand for a really good, clean finish.
 
If flatness is an issue, make sure if you get it sheared that the shop takes the shearing (twist) effect out of it for ya. It sometimes happens in longer thin strips like you are having done.
 
ive used this tool for years and cut hundreds of feet of sheet metal
the blade is still as sharp as new
this is 18ga metal ,thicker than what your cutting
to cut two feet ,if you have a steady had ,will take less than 5 seconds
they are cheap at harbor freight
notice how I started close to the edge with no problem
you will loose about 1/4 in where the curl is ,the thickness of the blade
tom
 

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mot said:
ive used this tool for years and cut hundreds of feet of sheet metal
the blade is still as sharp as new
this is 18ga metal ,thicker than what your cutting
to cut two feet ,if you have a steady had ,will take less than 5 seconds
they are cheap at harbor freight
notice how I started close to the edge with no problem
you will loose about 1/4 in where the curl is ,the thickness of the blade
tom
Click to expand...
So, what is it and where'd you get it?
 
If you have to buy the steel, then for sure I'd have the steel yard shear it for you.

If you already have the steel, then the tool Tom shows in reply #11 is the way to go.

I'm not a big fan of grinding steel, but have done it when I had no other way. Once I got a steel spec caught in my eye and was in great pain for 3 days until I finally went to the doctor. He had it out in seconds, but at a cost of $360. :mad: Think of the Model A parts that could have bought.:)
 
if you want clean straight cuts with no or very little clean up have the sheet metal shop cut them, labor can get very expensive,especially if you make a mistake and have to spend several hours fixing it
 
I have a major disdain for those electric shears pictured. I lucked out twice and got a large and small single blade electric shear. Cuts like butter but expensive. However, I was in a resale shop in Monroe a month ago and saw an electric shear like mine for $50. If I didn't already have 2 I'd have grabbed it.

This type as well as the smaller type:

http://www.unclesamsretailoutlet.com/Black-Decker-12-GA-Heavy-Duty-Shear-p/4106.htm

You'll use it more than you think and if needed will cut a radius as well. Large, but you can turn em with practice and little to no distortion. Check those resale shops kids!!
 
Want a new tool? Plasma cutter - for about $1,500.00 you can cut sheet metal up to about a 1/4 of an inch. You could cut 4 foot of 18 gauge sheet metal in under 15 seconds. Much cheaper to have it done. The place you buy the sheet metal might cut it for free or real cheap depending on how much you by from them. Save your hands - have it cut. Bill
 
Ross/Kzoo said:
I've got a couple of projects coming up and need to some 18 and/or 20 gauge sheet metal into strips. Some will be 2" wide and some about 4" wide. The lengths will vary from 18" to about 4'. What will be the best way to accomplish this? I have a woodworking band saw. Would getting a metal cutting blade do the job. It's too thick for hand metal snips. Maybe but a pneumatic or electric shear? What would you suggest?
Click to expand...

Have it sheared at a metal shop is the best way.
 
If as sheet metal shop is out of the picture a Kett double cut is best for lighter stuff, for the heavy stuff a 4 inch or so angle grinder with super thin cutoff wheels really works well with a steady hand with some easy deburring after. The Chineese freight cutoff wheels do not work very well they wear way too fast, the best are Mastercraft sold at Menards.... I do sheet metal work for a living so both are used daily.
 
I use the poor man's band saw: A metal cutting blade in a Saber Saw. Tractor Supply has them in stock in our area. Should be 32 teeth or more per inch. Clamp the sheet metal securely and adjust cutting (moving) speed carefully. If the blade breaks, which it will, the blade is long enough that you can re-clamp the left-over piece in the saw and use that.
 
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