Cut metal without stretching?

For thin material, an abrasive cut off process with relatively slow feed is apt to create less distortion. This would work with complex shapes hard to cut with other tools. However, if the stainless that you are cutting is flat, power shears and perhaps hand shears will not create much distortion.

Richard

HotRod wrote:

One way we used to cut thin metal for electronic prototypes was to clamp it strongly between two pieces of 3/4" plywood, then cut at high speed with a lot-o-teeth carbide blade in a table saw.

LLoyd

Take it to a sheet metal shop and have them sheer it for you. Takes only a few minutes and shouldn't cost more than a couple of bucks.

Any grinding process will introduce considerable heat, so that's not a great choice. Shearing the material will leave a rolled edge, often curling the piece in question, so that's not a good choice.

You mentioned a band saw. If you use a base piece that has a slot the same size as the blade, and use a very fine toothed blade in the saw, you can usually saw parts in thin stainless without distorting them. The key is to use the narrow slot support, and not push hard, for stainless is notorious for stripping teeth from the blade. If the blade starts shucking teeth, you have nothing to lose, so you can usually run the speed up considerably and get the job finished, although it will continue to shuck teeth. Time your feed rate in keeping with the missing teeth to minimize losing more----

To avoid scratching the material on the bottom side, from sliding in chips, tape some heavy paper on the bottom side of the part, while you're sawing the profile, or a couple layers of masking tape. Or, keep the bottom side the bottom, so when they're installed the scratches won't show. It's hard to avoid scratching the bottom face when using a band saw.

Harold

I already tried sending the metal to shop to have it sheared and it ended up deforming the sheared side enough that it rolled on the edge a bit. I'll try the bandsaw idea and see how that works.

You do know that you can get stainless with either a plastic film or a paper protective coating applied. Allows you to do quite a bit of work without marring the finish surface, although it won't stop shearing deformation (warping). Makes it a bit easier to hold too. You could probably do the same thing with un-coated on your own using something like MacTac, but I have never tried it.

I have tosn of 4' square sheets of stainless, galv. aluminum and other stuff that I got for free. I want to start workign with it instead of trying to buy somethingelse. BUT thanks. I'm going to give the bandsaw a try this weekend.