Cutting Stainless Steel

Space Teams Metal Shop
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We continue to live and learn new things in the metal shop. And we’ve recently learned that our primary saws, the horizontal and vertical bandsaws and the cold saw, will not cut stainless steel at all, and you will destroy the blade if you try. We hadn’t encountered this before; indeed, the vertical bandsaw and cold saw list appropriate speeds for cutting stainless steel. These were based off charts and calculations, not experience; experience has trumped these.

We’ll update the charts and add appropriate signs, but from now on, do not attempt to cut stainless steel on either bandsaw or the cold saw. (And attempt is the right word, because you’ll get little more than a scratch on your piece if you try.)

So how can you cut stainless steel if you need to? The thing I tried that worked best was actually a cutting wheel on an angle grinder. This in turns suggests that our abrasive chop saw would work as well, since it’s basically a huge cutting wheel. This tool has been made more accessible, but it is a strictly “at your own risk” tool that we haven’t covered in the metal shop safety classes. It’s vise is not at all as secure as I would like, it will generate a ton of sparks and heat while cutting, and the “blade” is basically a giant Dremel wheel, which will sometimes disintegrate just like its smaller cousin, much less often but far more violently due to its size. (I have experienced this personally, which was not fun. I may mount the remnants of the wheel somewhere as a warning.) Face shields are required when using this tool, and be mindful of where people are around you.

We will add a new option soon. We purchased a third-generation Evolution metal chop saw a few months ago; we just hadn’t figured out where to set it up. We will sort that out, and we will purchase appropriate blades for cutting aluminum, regular steel, and stainless steel. This will also be an “at your own risk” tool; the blades are safer, and the vise is supposed to be vastly improved over its predecessors, but it will still throw sparks and small cutoff pieces around. Face shields will be required for it as well.

If you have any uncertainty about using these smaller chop saws, please talk to a steward for assistance.

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I will add the same stainless steel we were using machined beautifully on both the lathe and mill, using carbide tools with appropriate speeds, cutting fluids, and cut depths.

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In March I used the bandsaw to cut my 2mm thick 304 blanks for this project:

I cut three blanks, 21 linear inches total, and I didn’t notice any changes in the rate of cut or in the chips that were generated. I used the magnetic container of cutting oil.

There are many types of stainless steel, and the dimensions make a big difference, too. I remain mostly ignorant as to the metallurgical nuances. I know that stainless work-hardens if your feeds and speeds are too conservative.

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Which bandsaw?

I’m coming to the impression that the issue may indeed be the type of stainless. One of the pieces that damaged the blades was of unknown provenance, the other was 316 Stainless, which is known to be harder to machine – except that it machined just fine; we only had problems cutting it.

Has anyone else cut stainless steel on the bandsaws? If so, what alloy was it?

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Everything I have cut was drops from Metals4U, alloy unknown.

However, a very strong magnet will just stick on the cut edge (but nowhere else) which based on my googling, suggests that it is not 316, but more likely 304.

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I used the DoAll bandsaw.

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