Obtaining or making 1/8" AL stock flat?

[SRT Mike]

I have a project that is basically made of two halves, each 1/8" thick.

I cut a recess in the bottom side for some electronics, then I cut a hole in the front side for switches and screws... the two halves screw together to make the finished part.

But I notice that when I get 1/8" stock in sheets from the supplier, the panels are bowed. The pieces I am using are about 12" x 12". I can't really just try to bend them flat, since there would be springback (plus I really don't need to be doing that extra work).

When I get 1/4" stock, it is dead flat. I heard once it's based on the process used to make it, rolled vs. extruded. I also heard that the process affects how well it anodizes, which may be true since I have parts made from thick stock that anodize great, and parts made from thin stock that look like crap.

Short of buying thicker stock and milling it down to 1/8" (which is hugely wasteful), anyone got any ideas? Is there some type of stock or some supplier where I can get thin 6061 AL and have it be flat?

Thanks

[Geof]

Search around for flat 1/8" it is available; well flat to within 0.005" to 0.01" over 12" anyway.

We use a lot of 1/8" and sometimes it is very good sometimes it will have a 1/32" bow in 12".

If you do try the route of machining 1/4" I suggest getting some small pieces first for a test. You may find it bows even more when you relieve the stresses by taking some off.

[Shotout]

Originally Posted by SRT Mike I have a project that is basically made of two halves, each 1/8" thick. Short of buying thicker stock and milling it down to 1/8" (which is hugely wasteful), anyone got any ideas? Is there some type of stock or some supplier where I can get thin 6061 AL and have it be flat? Thanks

Just a thought but can you vacuum clamp it with the convex side up so that it pulls down and your machining would be true and once it is screwed together each side would be pulling against the other and the true locations of the screws would hold it flat? If that would work for your parts and their finished application it would eliminate concerns about inconsistent supply or wasting material.

[ger21]

Can you get cast tooling plate in 1/8"?

[mc-motorsports]

They are probably shearing it to size, hence the warping. You could order a full sheet and plasma cut it and finish cuts on a band saw.

[SRT Mike]

Sorry to reply to this late, got tied up on another project...

I am not sure it's from shearing, it almost looks like they came off a giant roll of material. I got about 30 sheets of 1/8" stock, 24" wide by 48" long. They have at least 1/2" of bow along their length. When they are stacked up, they line up perfectly, like jigsaw puzzle pieces.

I will check with the supplier to see if they have something flat.... I could never use the stuff I have other than for testing. Can't really screw the two halves together and rely on that keeping them straight, plus, I feel I probably shouldn;t have to

[Geof]

1/2" in 4 feet is appalling; that is about 0.01" per inch. I have a piece of 1/8" 6061 sitting on my desk that is within better than 0.002" over 7 inches so it is possible to get it straight.

[Shotout]

Originally Posted by SRT Mike Sorry to reply to this late, got tied up on another project... I am not sure it's from shearing, it almost looks like they came off a giant roll of material. I got about 30 sheets of 1/8" stock, 24" wide by 48" long. They have at least 1/2" of bow along their length. When they are stacked up, they line up perfectly, like jigsaw puzzle pieces. I will check with the supplier to see if they have something flat.... I could never use the stuff I have other than for testing. Can't really screw the two halves together and rely on that keeping them straight, plus, I feel I probably shouldn;t have to

Yea Gods that is bad. I figured you where talking 1/32 to a 1/16th over the length.