Bending aluminum plate

Yeah ... I don't think that I'm going to be trying that.

Another good reason to try bending some trial pieces.

Thanks, Bob

7075 is a heat treatable alloy. You can anneal it in the same way, and it will age harden

You almost need a rosebud propane torch - weed-burner head if the peice is large.

Anneal by putting acetylene soot (rich flame) on the line to be bent, and then heating with a neutral flame until it burns off the soot.

And bend (shortly afterwards) at right angles to the grain from rolling. It will crack a *lot* easier if your bend is parallel to the grain. (The grain often looks like single directional sanding.)

If it is a hardened alloy (e.g. 6061-T6) it will regain some of the hardness over a period of time following the annealing, but it is not likely to fully recover the T6 hardness.

If you are not sure about which direction the grain runs, before the bending for real, cut off a bit of scrap stock (maybe 1" wide by

8-10" long) from two edges at right angles to each other, and try bending each along the long way. See which cracks. Once you find the right direction, cut off some more and experiment with radius, but you probably want the centerline radius to at least be twice the thickness of the aluminum.

Good Luck, DoN.

My limited experience bending aluminum has had the results of cracking when bending cold, success when heated with a propane torch. The aluminum I bent was 3/8" thick X 3/4 width and a 3/4 radius bend.

RogerN

Bend across the grain if it's mystery alloy. Bending parallel with the grain will often result in cracking. If you have options, select the largest possible radius for the bend. Study the surface to determine which direction the grain runs, or, if it's marked by any means, you can safely assume the marking to be parallel with the grain.

If you have any questions, and can tolerate the material being annealed, blacken the surface with an acetylene torch, then preheat until the carbon burns off. Quench in water, then make your bend. Be careful, as you'll be working near the melting point.

The annealing process may or may no be necessary. Not all aluminum grades are amenable to age hardening, so there may be no benefit in the heating process.

Harold