Why Are My Aluminum Plates Warping After Extrusion and Cutting?

[XiangYan]

Hi, I get a whole bunch of extruded Al plates. Each of them is about 7" long by 3" wide and 0.08" in thickness. They are extruded parts and cut into 7" long on each pc.
However they are coming out wrapped, not substantial but quite a amount that is out of our tolerance. They are wrapped close to half mm on the 3" side and even worse (I guess 1mm~2mm) on the 7" side.

I wonder if this warp is introduced during the extrusion, or during cutting. I looked at typical 8020 parts, they look perfectly flat.


Thanks!

 

[SteamKing]

Are your parts wrapped or warped? There is a difference.

 

[XiangYan]

Sorry, maybe a typo, I mean wrap, means a curvature on the surfaces.

 

[jim mcnamara]

warp as in 'not flat' ... I would worry more about what specs did you give the vendor on the Purchase Order. Without something in writing it will be hard to get the vendor to replace/redo/repair the work. I do not think it matters how the parts were damaged, unless it happened after you received them.