Technical How do you cut sheet metal ?

If I have to choose one tool to cut sheet metal, I choose my air saw. It cuts curves, over beads, no sparkels but it's not the fastest tool, but I'm not in a hurry working on my own rod. Be sure to wear thick gloves - it vibrates and ear protection

 

I have, up to this point, used the crap out of my 4-1/2 electric grinder and air die grinder with cut off wheels. These work good even with outside curves but terrible for inside curves.

I have considered both elect nibblers and elect shears. I guess I'll look into some right and left tin snips too along with the small air saw..

Thanks guys appreciate the ideas and feedback on how well each work...

 

For decades I fought my way through cutting with hand snips. And if I needed clean straight cuts I ran to the local sheet metal shop and had him shear it.
Then about 18 months ago I started my latest project that I knew was going to require more sheet metal cutting than anything before had. So I looked around, and settled on a electric shear that has the 3 jaws. One of the best tools I've ever purchased, and it does a great job for long straight cuts, and gentle curves. It will not do tight curves, and I gave up trying to use it for that. But I do use it to rough out tight curves, and then final trim them by hand with snips.

 

sorry no picture, but my neighbor had a slick cutter he copied from the old blacksmith in his homeland, Finland. it was a straight section of hard steel, like a chunk of a cutting edge from a plow 2' long ground sharp, with a chunk welded on one end to clamp it in the vice when needed, and a pipe welded on the end for the other blade to pivot. then, a leaf spring about 3' long with one edge ground square and true, a bolt thru the spring eye to the pipe on the flat steel and now you have a 2' scissors. it really worked quite well.

 

we need a picture.

 

Ron Covell just posted an excellent video explaining how to use snips...

 

I use a throatless shear for most metal cutting.

 

For small work I found that my HF bandsaw with the table attachment is very useful. Oh yes, save on band aids too

 

Nibbler but as steve said the clippings are a pain on the high end plasma. https://www.harborfreight.com/16-gauge-air-nibbler-96661.html

 

I had a tool that I just sold recently. It was called a "slitter" and it worked really well on making long straight cuts and even multiple cuts at the same time. It was "idiot" simple in design. It had two wheels that fit side by side and could be adjusted to any place on the shafts to accomodate different widths. Actually there were more than one set of wheels in case someone wanted to cut multiple pieces. Here are some pictures.




The reason I mention this, is that bead rolling machines often have wheels designed for cutting a sheet, and its the same principle as this machine. This slitter made cutting metal easy. I just wonder if anyone has used their bead roller to cut, or if its just not rigid enough. I always thought a rigid bead roller would be good for a lot of this cutting. I'm building a bead roller, so I guess I'll find out...........

 

Beverly B3 throatless shear.
Marshalltown rotary throatless shear.
Niagra stomp shear.
Electric shears.
Aviation snips.
Various cutoff wheels on the electric or air grinder.
Air body saw.
Round draw-through punches for holes.
Sawzall.
Plasma cutter.

I hate anything that generates grit or chips, so I gravitate to the tools on that list that do not.

It is not always possible to avoid the others.

Make sure you ALWAYS wear eye protection, hearing protection, and respiratory protection, especially with abrasive tools.

 

I did try the cutting wheels on my bead roller, but found that it distorted the metal. That was before it got re-enforced, but would prefer another method. Like Gimpy said, something that creates the least amount of dust, shavings, etc.

 

B2 Beverly shear was probably one the best tool purchases I ever made!!! Love it and no chips or dust.

 

Infinitely rebuildable, sharpenable blades, all replacement parts still sold, still made exactly the same way as day-one (except the name plate).

No reason not to buy a used one. Worth every penny. I have run more than a marathon of metal through by B3.

 

#1. A stomp or hydraulic shear, expensive
#2 a bench mounted shear, I have a Woodward fab one that does a great job.Beverly is the gold standard for those.
#3. Electric shears.
#4 hand shears.
#165. A cutoff wheel.
I guess it depends on what the cutting needs are.
A quality pair of aviation shears are a must.
My bench shear is much faster than a cutoff wheel. But a cutoff is a must for removing metal on the car most times. I cringe as a shop teacher watching all these guys use cutoff wheels without the guards.

 

Back in the days when I had employees, one of the shop rules was that if you removed a guard, for any reason but to repair an unplugged tool, you were fired on the spot. No excuses.

 

I cut the roof off of a Model A once with a skill saw with the blade turned around backward and a few hacksaw blades.

I have use some pretty expensive equipment to cut sheet metal in my time. but these days I use a sawzall and a jig saw more than anything else. They seem to fit my budget well.

 

An electric shear with some form of guide will cut a very nice straight line with no cleanup. I use my small air saw with cut up Lenox hacksaw blades a lot. Very rarely will I use my snips.

 

As I get older one problem I'm running into is that by Wednesday at work my hands are hurting so bad its hard for me to even use my frame hammer. The palms of my hands get so sore that using something like tin snips hurts greatly...

So being the wuss that I am, I'm looking for easier ways LOL !!

Always was curious about the nibblers, never been around one or had the chance to see one in operation so reading about their operation here has helped!

 

I have more mechanisms for cutting sheet metal than you would believe. Different situations call for different tools. It would take a long time to list them. For a floor pan, a saber saw or jig saw, an abrasive cutoff wheel and some red and green snips should enable you to get the job done. Forget the yellow snips. They are almost unnecessary.

 

I have a full Arsenal band saw, cut off wheels, chop saw, sawall, tin snips, body saw and o/a torches. So I have not used a hack saw in years

 

I like an abrasive cut off wheel for most cutting on the car. I’ve tried air saws. The short stroke and high frequency eats blades. You are only using the same 4 or 5 teeth on the blade, so it dulls quickly. A sawzall with a diamond blade lasts a long time, and doesn’t shake you or the material much.
For off the car, a stomp shear and a bandsaw are my go-to tools.

 

It depends on what gauge and how big, metal bandsaw, plasma, old Hercules hand shear, cut off wheels, saws all, aviation shears, recent garage sale favorite Milwaukee electric shears.


Sent from my iPhone using The H.A.M.B. mobile app

 

I have also used electric shears, air powered shears, recip saws, and nibblers. I found that the issue was that something like floorboard metal is thick enough that I have actually broken a shearing tool, so I was looking for a better way.
I have owned a Henrob (Cobra, Dillon) torch for years, and finally decided to use it to cut sheet metal, I was surprised to see that it works as well as the demonstration! Using the cutter, resulted in a very clean, narrow cut, with virtually no warpage. I was impressed.
Three years ago, I also purchased a plasma cutter. That also works extremely well.
Bob

 

https://www.jegs.com/p/JEGS/JEGS-Metal-Cutting-Circular-Saw/7687244/10002/-1

I bought this saw in the fall, there was a problem with the blade provided, but that was sorted out. Its great for straight cuts, (long or short) with no sparks.

Phil

 

Black Sharpie then with great care.

 

In a lot of ways, a nibbler is the most versatile of all cutting tools mentioned.
Pros:
You can change cut direction without stopping almost at will.
Curved or irregular-shaped cuts aren't a problem.
Very little depth is needed behind the piece being cut, so no worries about cutting anything behind the piece.
Leaves a very slightly serrated edge with little or no panel/edge distortion, also won't leave as sharp an edge compared to some other methods. You can reduce the serration by cutting slower.
No sparks, flames or dust, or worrying about exploding wheels.
Cons:
Generally limited to 16 gauge steel, although you'll get better tool longevity if you do 18 gauge and thinner. Will cut thicker aluminum, struggles with stainless (as do most cutting tools). Usually won't cut overlapping flanges. I have seen units that will cut thicker material, but you're out of the hobby market and into the pro one so prices go up sharply.
Can be hard to follow a cut line, a guide is highly recommended for precise cuts.
Won't cut around sharp bends, and can struggle with smaller bends in a short distance. Shallow ribs in a floorpan will usually be OK, deeper ones not so much. Gradual curves in exterior body metal are generally no issue.

And the big one, the 'fingernail' clippings these generate. These are fish-hook sharp and can fly everywhere, so doing whatever you can to limit their 'travel' will help. Wear eye protection and high-top shoes (and/or pants that cover the tops of them), keep pets and small children away. This is important; these can easily embed in feet (AMHIK) and if they get into a callus it might be days before you know it's there. Cover finished surfaces with plastic (not cloth; they'll embed in that too) and use a vacuum for clean up. If cutting steel, I'll put a large magnet near the cut to help collect them.

Probably the slowest powered cutting method, but not by a ton. If you don't have an edge to start your cut on, you'll need about a 5/8" hole to start it. They can get dull after a while under heavy use or abuse, but the HF units I use aren't expensive so I always try to keep a spare on hand.

 

Thanks Steve and everyone else.

It seems that a nibbler is definitely on the list!!

 

I made the mistake of buying a Trumpf brand nibbler. A high quality tool no doubt. Very much overpriced. The tool cuts well
but has high speed only. It is hard to control and follow a precise line. Due to the speed I feel. They offer a variable speed model
that I think would be much more controllable at about half
speed. An equal tool can be bought for a fraction of the Trumpf
brand. They also offer various special metal cutting tools. One
I saw demonstrated was a three blade type shear that had a feature that would shear off the curl of cut with the touch of a button that lets the operator continue to cut without stopping
to deal with the waste curl as it emerges from the cut. It was
the same price as the nibbler and I think it would have been
much more useful for my endeavors. As others have stated
the little crescent shaped debris from the nibbler are difficult
to contain and must be cleaned up as you go. I have used an
industrial nibbler to fashion 1/4 plate into intricate shapes
on a radio wave proof room cladding. It cut slower and was easy
to control even on thicker plate.

 

45 or so years ago I would use a cutting torch followed by snips.
When using the torch keep the flame directed away from the part you want to keep and cut roughly a half inch from final cut line.
All the distortion will be within that half inch.
Use the snips to trim the distorted edge for the final cut,
then smooth the edge with light hammer and dolly work.
And weld it up with a 00 tip in the OA torch.
I have more options now so haven't done it that way in a long time but it worked just fine.