Best way to cut sheetmetal

[Ross/Kzoo]

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?

[BRENT in 10-uh-C]

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.

[karasmer]

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.

[Kevin in NJ]

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.

[Charlie Stephens]

Can you have the store where you buy the metal cut it with their professional tools?

Charlie Stephens

[MikeK]

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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?

[Ross/Kzoo]

Originally Posted by MikeK

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?

Thanks, no I have a prior commitment so I can't make it. I really wish I could.

[mass A man]

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.

[ctlikon0712]

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.

[mot]

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

[5window]

Originally Posted by mot

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

So, what is it and where'd you get it?

[Tom Wesenberg]

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. Think of the Model A parts that could have bought.

[ford3]

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

[tbirdtbird]

I have the same tool:
Kett electric hand-held shear:
http://www.expresstools.com/Kett-KD-...FUVp7AodQRkACA
is one source.
there is no distortion, because the distortion is in the 1/4" wide waste strip.
Have used this tool for years

[theHIGHLANDER]

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...ear-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!!

[Bill in SoCal]

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

[Mike V. Florida]

Originally Posted by Ross/Kzoo

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?

Have it sheared at a metal shop is the best way.

[tbirdtbird]

that Black and Decker is actually a nibbler, and very pricey, at that.

[karasmer]

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.

[Richard Lorenz]

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.

[ford3]

all of the above suggestions and tools are good, but there is no way to cut a perfectly straight line by hand, if you need clean straight cuts find a shhet metal shop to cut them, shop around till you fond a shop thats reasonable, if you buy the material from them they will be more willing to work with you on price

[Kurt in NJ]

At work a bench shear arrived, I laughed at it, but have grown to like it --it has about a 12" cut, not too hard to cut a sheet in a straight line --i have seen them for 100$ --this one on enco sometimes has free shipping --http://www.use-enco.com/CGI/INPDFF?PMPAGE=672&PMCTLG=00

I havn't seen the most baisic method --cold chisel and hammer mentioned ---but going the the sheet metal shop is good advice

[Tom Wesenberg]

Originally Posted by Kurt in NJ

At work a bench shear arrived, I laughed at it, but have grown to like it --it has about a 12" cut, not too hard to cut a sheet in a straight line --i have seen them for 100$ --this one on enco sometimes has free shipping --http://www.use-enco.com/CGI/INPDFF?PMPAGE=672&PMCTLG=00

I havn't seen the most baisic method --cold chisel and hammer mentioned ---but going the the sheet metal shop is good advice

LOL, when I was 12 that's how my dad and I removed the sides and top from his old 1950 Studebaker, so I could have a field car for the back 40.

Sure wish I had that car back in good condition, like it was before we cut it up into a field buggy.

[Joe K]

I'm in the middle of putting new patch panels on the bottoms of a spare pair of CC pickup doors.

The best I've found is to use a 4" grinding wheel in either an air grinder or an electric grinder. You can buy the 4" wheels in 0.035 thin-ness and following a line is not hard.

The wheels are available at www.mscdirect.com and are
MSC #: 59963223


It leaves a cut virtually distortion free and any imperfections/unstraightness can be removed with a file held perpendicular and longitudinally.

Air grinder available at Harbor Freight.



The 90 degree version may be easier to use but I don't own one.

Don't forget the mandrels.

Joe K

[Pete]

You say you have a wood band saw.
How much horsepower does it have???? 1/2 or more??
Will it mount standard 16 or 18 tooth metal cutting blade????
An old worn out blade works fine for FRICTION SAWING.
Clean the wood dust out of the saw first.
Run the saw on it's HIGHEST speed and wear a welding jacket, gloves and a full cover face shield.
There's going to be a lot of hot chips flying around. Some will be red hot.
Clamp some kind of ripping fence on the saw table.
Have at it. Feed as fast as you have horsepower to keep the blade speed up to maximum.
As strange as it seems, there is almost no heat spread into the sawed parts.
It all goes out in the kerf.
Oh, by the way, it's going to be noisy. Wear ear muffs.

[Ted Duke]

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Back in 1972+ I did a lot of it with an old Sears Craftsman saber saw and LOTS of steel cutting blades (it was all I had), but NEVER AGAIN, now I borrow my sons old electrics nibbler until I buy one.

[nospartsman]

Cutting a couple strips can be done without buying anything, by using a sharp scribe, a straight edge and your hack saw. If your strips are only a couple inches wide as you mentioned, use the hack saw for the 2 inch side and score the long dimension several times and score the back side also, use some pressure. When you think you have scored it enough take a couple crescent wrenches or vice grips to grab the strip and move it up and down til it cracks off. If it starts to bend near the score edge, you didn't score it deep enough. Take a file to dress the raw edge and you're done. If you don't have a strong scribe, sharpen a nail set to a point, they're harder than sheet steel. Problem solved no tools bought, money spent. Not the best way, but the cheapest.

[howie123]

I have heard that a bandsaw can do a nice job on sheet metal if the blade is reversed. That is the teeth are pointing up and running quite fast. I haven't tried it myself.

[theHIGHLANDER]

Originally Posted by tbirdtbird

that Black and Decker is actually a nibbler, and very pricey, at that.

If you mean what I posted, no it's not a nibbler. A nibbler removes a little crescent of metal as it cuts. I hate those too.

This is a shear:


This is a nibbler: