Sheet metal cutting basics

[MC]

When it comes to metal tubing or rods or anything i can fit in my chop saw, I can use a cutoff blade and get the job done (albeit cutting a one inch thick wrought iron post isn't pretty with a cutoff blade, it eventually gets the job done).

What's the best tool, and what are the best techniques, for cutting sheet metal, say, up to 1/4 inch thick? How does that change when you go down to thinner material?

 

[Yomax4]

Plasma for me. Some Oxy-fuel and small cutoffs.

 

[flyerdan]

Plaz, skinny-wheel or 3" air cutter for notching or irregular cuts. For straight cuts, especially in the .250 plate, I've got a Porter-Cable 440 circular saw. Can't find one online anymore, it's similar to this.
It really came in handy when I was making my extended forks; got 2 4x8x7' I beams and a chunk of .250"x9" flat bar for $40. Cut some triangle and makeup pieces to get 8 foot at the tips

 

[Gary Fowler]

Other than a plasma torch, when cutting thin sheet metal, a metal cutting saw is probably the best method. The less heat input, the less warpage you will get. The Evolution hand held saw is likely your cheapest option and the best choice for thin (or even thick) sheet metal and even some structural shapes.
That is going to be my next purchase. I cant decide on a stationary chop saw or hand held though. I already have an abrasive chop saw that works OK but the sparks are horrendous and the NOISE.

 

[flyerdan]

Gary, I'd recommend the hand held saw. It can be used for angle cuts on larger pieces or ripping a sheet. Plus, they cost far less than a chop saw version, you could probably search craigslist and find a HF style bandsw and get that and the circular saw for about the same as the chop saw, then you'll have all the bases covered.
The reason I have one is that we had to make some enclosures out of louvered material, 4x8 sections of what looked like 14ga. steel window blinds. It was the kind of stuff that would cause a plaz to start and stop and eat consumables, and a skinny wheel would eat away in about two feet of cutting, if you managed to get that far without grenading it.

 

[MC]

Other than a plasma torch, when cutting thin sheet metal, a metal cutting saw is probably the best method. The less heat input, the less warpage you will get. The Evolution hand held saw is likely your cheapest option and the best choice for thin (or even thick) sheet metal and even some structural shapes.
That is going to be my next purchase. I cant decide on a stationary chop saw or hand held though. I already have an abrasive chop saw that works OK but the sparks are horrendous and the NOISE.

I made about 80 cuts with the chop saw through half inch wrought iron... that nose must have made me quite popular with the neighbors. It's quite hideous.

 

[Yomax4]

I have 2 Evolution saws. One large chop and a slide miter. Both are as loud or louder than anything that makes noise. Still quicker for angles and are more round stock friendly than my band saw. The large chop saw has only made a few cuts and I'm trying to swap it for a mag drill. The rep is a friend so I get my saw blades for free.

 

[CA_Bgrwldr]

When it comes to metal tubing or rods or anything i can fit in my chop saw, I can use a cutoff blade and get the job done (albeit cutting a one inch thick wrought iron post isn't pretty with a cutoff blade, it eventually gets the job done).

What's the best tool, and what are the best techniques, for cutting sheet metal, say, up to 1/4 inch thick? How does that change when you go down to thinner material?

Depends on the gauge. For up to 14 gauge, I preferred to use a shear or nibbler. For anything thicker, used to use a cut-off wheel for short sections, or my circular saw(worm gear skillsaw) for long sections, however, now I use my plasmas due to being quicker.

 

[California]

You guys have ALL the toys! ???

My HF handheld band saw using quality blades from an industrial supply place, or a cutoff blade on an angle grinder, are all I've needed so far.

Here's a photo cutting cast iron. I hogged out grooves in wheel weights to adapt them for my tractor. (To avoid interference with the valve stem). The cuts with the bandsaw were the same as I would do as the first step to notch a piece of wood.

But jamming a chisel into the cast iron cuts didn't break off any chunks. So for this project, just starting with the big angle grinder would have worked as well.

 

[Gary Fowler]

You guys have ALL the toys! ???

My HF handheld band saw using quality blades from an industrial supply place, or a cutoff blade on an angle grinder, are all I've needed so far.

Here's a photo cutting cast iron. I hogged out grooves in wheel weights to adapt them for my tractor. (To avoid interference with the valve stem). The cuts with the bandsaw were the same as I would do as the first step to notch a piece of wood.

But jamming a chisel into the cast iron cuts didn't break off any chunks. So for this project, just starting with the big angle grinder would have worked as well.

View attachment 1357View attachment 1358

Likely the reason it didnt break off any chunks is because it is cast steel rather than cast iron. Most folks think tractor axles/frame/ weights etc are cast iron when it is really cast steel and can be welded cut etc very easily.

 

[Gary Fowler]

Gary, I'd recommend the hand held saw. It can be used for angle cuts on larger pieces or ripping a sheet. Plus, they cost far less than a chop saw version, you could probably search craigslist and find a HF style bandsw and get that and the circular saw for about the same as the chop saw, then you'll have all the bases covered.
The reason I have one is that we had to make some enclosures out of louvered material, 4x8 sections of what looked like 14ga. steel window blinds. It was the kind of stuff that would cause a plaz to start and stop and eat consumables, and a skinny wheel would eat away in about two feet of cutting, if you managed to get that far without grenading it.

I have an old Milwaukee band saw already so the hand held saw might be the ticket.

 

[CA_Bgrwldr]

You guys have ALL the toys! ???

I didn't start with them, just acquired them over the last 16yrs or so. When I started fabricating, all I had was my skillsaw from my carpentry days and a bench grinder. I built many a plate bumpers, rock sliders, and gear racks for off road trucks with just those two tools, then picked up the other tools to make life easier.

 

[Gary Fowler]

Back when money was extremely tight (wife, 5 kids, granny and great granny to take care of), I used to save to buy one small hand tool each month(a specialty wrench, hammer, saw etc). Larger tool sets maybe one a year (combination socket/wrench sets) . Birthdays and Christmas, I got tools or gift cards to buy tools.
Now I can afford to buy just about any tool I want but I have just about every tool one could need for welding, mechanic or carpentry (carpentry is my least favorite thing to do)

 

[California]

Back when money was extremely tight ...
Now I can afford to buy just about any tool I want but I have just about every tool one could need for welding, mechanic or carpentry (carpentry is my least favorite thing to do).

Similar here. I still have the Craftsman beam torque wrench I bought for my first engine repair, way back while JFK was president. $10 and that was my only major tool purchase for years. Every other tool was mismatched yard sale junk my father had accumulated. Using any of that was a big time suck.

Later when I could afford it I bought decent stuff. For example the Craftsman socket set. Still thinking cheap, one of my Craftsman ratchets is stamped 'Rebuilt'. It still works fine years later. The Skil 3/8" drill I used for years was a Rebuilt too. More recently, stuff from HF. Not tradesman quality, but sufficient to get work done. The few years I was a journeyman Carpenter was the only era when I bought best-available tradesman tools.

Now retired, I could easily afford a pride-of-ownership welder etc. But I don't really need it so I haven't gone off in that direction.