Cutting Stainless 24ga Sheet - Clean Edge?

I've cut a number of thin stainless sheet cooker extractor covers and found the best way is to cut with a angle grinder using a thin disk (1mm) and do so in a number of light passes rather than trying to cut through in one go. Less heat input with light cuts leads to little to no heat discolouration at the cut. I put masking tape on the stainless and clamp a piece of bar as a cutting guide on the side to keep if possible in case a slip marks the surface.

If you can find an archive of old usenet articles, look for articles about cutting stainless with a high speed bandsaw. The "high speed" discussed was in the range of wood cutting saws and blades that had lost their teeth worked as well as those with.

Hul

Bob La L> Other than a big well adjusted hydraulic shear is there a practical way

In a recent (few months maybe) video from Fireball Tools they also showed that the discs last longer by light tracing vs through cutting, but it takes longer.

Joe Pi recently did a video showing cutting thin sheet with the blade reversed on the bandsaw. Unfortunately I don't see any practical way to run a 4x8 sheet through my small shop size band saw. Honestly I didn't think Joe's results were as good as he made them out to be. Of course often things look different on camera as opposed to in person.

If you can find an archive of old usenet articles, look for articles about cutting stainless with a high speed bandsaw. The "high speed" discussed was in the range of wood cutting saws and blades that had lost their teeth worked as well as those with.

Hul

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I contributed to that old thread, having done it after the teeth dulled, the cut heated red-hot and the blade kept cutting anyway. When the front edge rounded and bulged unevenly I reversed the blade and friction-cut with the back side. The edge wasn't pretty but it cleaned up well enough for the interior of the industrial oven I was modifying. IIRC it worked at <100 FPM initially, but better and with less pressure when faster. I think a small air rotary or belt sander would clean the edge up as nicely as they do on sheet steel.

My go-to tool to cut sheet metal thicker than the 30" shear/brake/roll can handle is the Enco version of this:

cuts straight or convex but not concave; the concave side cut-off is strongly bent.

I have the double-scissors and round punch types of sheet metal air nibblers. The round punch cuts the smallest concave curves and the scissor can handle large sheets, like a damaged above-ground pool I cut into manageable sections. Both wander off the cut line more easily and may need more edge cleanup than the 8" bench shear. After knocking off the burr I straighten and flatten the cut edge with a planishing hammer and anvil, which makes it easier to file smooth. The round punch tool makes nasty pointed chips that are difficult to collect unless they are magnetic.

A corner notcher is a nice free-hand precision shear for small work.

is the old model 100 so I cut only thin steel, brass or aluminum on one side. jsw

24 ga stainless might be OK with one of those powered metal shears with the pistol drill handle. Use oil, it makes a difference.

That has a straight blade, right? How about a Beverly B3? Cuts very cleanly provided it's sharp and adjusted. (Otherwise a bit of burr to clean up -- what the OP wants to avoid..) But it will cut curves in both directions.

I watched that one too . And I like David's use of a piece of flat bar as a guide . My cutoff disc cuts always look like crap ...

That has a straight blade, right? How about a Beverly B3? Cuts very cleanly provided it's sharp and adjusted. (Otherwise a bit of burr to clean up -- what the OP wants to avoid..) But it will cut curves in both directions.

Mike Spencer Nova Scotia, Canada

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I've seen only one Beverly shear for sale, priced too high to justify, so I can't review a tool I haven't used. My guess is that it could be difficult to see and closely follow a line from the far side of the sheet, unlike with manual aircraft shears which can cut a sheet stood up on edge. That's a problem with the 8" bench shear too.

Most of my sheet metal work is making repair parts and electronic housings, which generally requires straight cuts. I'm not very artistic and don't design curves unless necessary for auto body rust repairs, where they hopefully will disappear after welding.

I watched that one too . And I like David's use of a piece of flat bar as a guide . My cutoff disc cuts always look like crap ... Snag

--------------------- My cutoff disc cuts do too, but it's about the only fast and easy way to cut corrugated steel roofing.

I bought a couple of $15 angle grinders that overheat rapidly and set them up for the quick cleanup jobs like smoothing cut edges and wire-brushing rust or slag, so I don't have to keep changing the disk on the good angle grinders, or risk them by grinding concrete or rocks. The 4-1/2" cheapies aren't up to cutting out a bad weld so I bought an inexpensive light duty 7" grinder and leave a reinforced cutoff disk on it, and a saucer disk on the good 7" Porter-Cable to smooth or flatten the welds.

The longer life is easy to understand; the lower the angle of attack (shallow cut) the less the disk gets bits torn from its circumference.

But regarding clean cutting, if the disk *only just* reaches through the steel, the circumference is moving parallel to the lower surface, not laterally through it. So the burr is not pushed away from the surface.

The exact same principle applies when cutting melamine board with a circular saw; adjust the blade to only just penetrate the board, and you get a much cleaner cut with less chipping of the melamine surface.

2 plasma 3 water Time for a new tool!

I don't know how far from the edge you need to cut but another possibility is a set of shearing dies on a bead roller. I have a manual bead roller from Harbor Freight that's no longer on their web site with a 19" throat that came with several bead and flanging dies along with a set of shearing dies. It can handle 20 ga steel but to roll beads on the ends of 3" OD 16 ga 304SS intercooler piping I added a support strap right next to the dies to reduce the throat to about 1" :-). I've mostly done beads and played with a few flanges, and never actually tried to cut anything so I don't know how clean the edge would be. Eastwood has an electric bead roller and shearing dies to fit it, but those dies won't fit their manual bead roller. A quick google search turned up several other brands online but I didn't study the specs. You could also turn your own set of dies if you already have a bead roller. The advantage compared to a Beverly type shear is that the cut would be continuous so easier to keep straight over a long distance and no little jaggies every few inches as you reposition the sheet for the next short cut.

Laser or water jet would be awesome. Space/power/money. Pick any two and I don't have the third one either. Seriously though those are good options. Just out of my budget. Plasma might be possible, but the size could be an issue. As little as I would use it a Langmuir table and an import plasma might be ok for this thin stuff. Maybe I can get SWMBO to take it out of her play money since its for her project. LOL

Maybe I'll do some looking around on YouTube and see if I can watch somebody doing that kind of cut on a bead roller.

Laser or water jet would be awesome. Space/power/money. Pick any two and I don't have the third one either. Seriously though those are good options. Just out of my budget. Plasma might be possible, but the size could be an issue. As little as I would use it a Langmuir table and an import plasma might be ok for this thin stuff. Maybe I can get SWMBO to take it out of her play money since its for her project. LOL

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The local MakerSpace has a CNC plasma cutter and makes arrangements with small businesses, such as renting them space. You could contact yours and ask.

Some years ago a nearby steel supplier told me they had a plasma cutter that could follow a drawn line. They may have meant it would copy from the drawing to a metal sheet beside it.

Then again...

Ok, This is an official YOU SUCK. LOL. I found a couple videos of guys using bead rollers to shear sheet metal and I have to admit I am impressed with the possibilities. I wish that was the end of it. Unfortunately I went down the rabbit hole. A relatively cheap (not the cheapest) bead roller would probably have done the trick for he original project. Making/sharpening/modifying bead roller dies is well within my capabilities. Then I started looking into the various capabilities of bead rolling. It will do some cool things. I have a dozen new projects in mind, and its a very possible answer to some other projects I already wanted to do. Now I want one of those 36 inch throat Baleighs that will form 10 gauge.

Seriously though. Thank you. I may not go that way for this project (I might), but I definitely got a different mental grasp of the scope of a bead roller. Previously I pretty much though of it as a toy for making oil can lids to weld into the floor boards of project cars. Now I realize it can be so much more depending on the tool. Thank you again even if I do have to add another 8 grand to my tools wish list.

There is a tracer type setup (not sure what it is called) that will literally follow a black line on a white background. A local fabrication and industrial shop I know of has one setup with big industrial cutting torch heads. I think they called it a pantagraph, but I also thought a pantagraph had a stylus. I guess it could be an optical stylus. Its not a cheap machine.

I don't know of a Maker Space here in Yuma, Arizona. I've thought about creating one, but I really don't want to share my machines with folks that didn't pay for them.

Ok, This is an official YOU SUCK. LOL. I found a couple videos of guys using bead rollers to shear sheet metal and I have to admit I am impressed with the possibilities. I wish that was the end of it. Unfortunately I went down the rabbit hole. A relatively cheap (not the cheapest) bead roller would probably have done the trick for he original project. Making/sharpening/modifying bead roller dies is well within my capabilities. Then I started looking into the various capabilities of bead rolling. It will do some cool things. I have a dozen new projects in mind, and its a very possible answer to some other projects I already wanted to do. Now I want one of those 36 inch throat Baleighs that will form 10 gauge.

Seriously though. Thank you. I may not go that way for this project (I might), but I definitely got a different mental grasp of the scope of a bead roller. Previously I pretty much though of it as a toy for making oil can lids to weld into the floor boards of project cars. Now I realize it can be so much more depending on the tool. Thank you again even if I do have to add another 8 grand to my tools wish list.

---------------------- Just think what sheet metal workers used to do with hand tools: