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Unread 02-04-2016, 11:50 PM
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7075 sheet metal

Apparently our teams sponsor bought us some 7075 .09" sheet metal. Normally I would be jumping with joy due to the durability of 7075 aluminum but I am a little nervous due to the fact that we have to been it. We already sheered a bolt on our sheet metal sheer after trying to cut it. So my big question is what can I expect when working with 7075 sheet metal?
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Unread 02-05-2016, 12:00 AM
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Re: 7075 sheet metal

You can expect to have a hard time bending it! but you can drill it and rivet it to other pieces, such as aluminum angle, to make the shapes you need.
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Unread 02-05-2016, 12:18 AM
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Re: 7075 sheet metal

It's hard to form (bend, punch, etc.) and apparently hard to machine (although personally I haven't experienced problems there, as it is still aluminum) but it is very strong. Drilling and riveting/bolting is the best attachment method, and to cut it I use a bandsaw or chopsaw.
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Unread 02-05-2016, 12:23 AM
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Re: 7075 sheet metal

Quote:
Originally Posted by asid61 View Post
It's hard to form (bend, punch, etc.) and apparently hard to machine (although personally I haven't experienced problems there, as it is still aluminum) but it is very strong. Drilling and riveting/bolting is the best attachment method, and to cut it I use a bandsaw or chopsaw.
7075 should cut/mill/turn much the same as 6061. In many cases better, since it is less gummy. HSS has no difficulty with it whatsoever.

Everything you said about forming it is correct though. I would say it's basically useless for FRC if you want to bend it.
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Unread 02-05-2016, 03:08 AM
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Re: 7075 sheet metal

Further, if I understand my research into aluminum grades a few months ago correctly, bending 7000 series (or 6000 series) aluminum with a tight radius disrupts the temper, greatly reducing the advantage of the aluminum grade unless you re-temper the piece. Many aluminum products with bends are made of 5052 for this reason; it has good strength without tempering and despite fairly tight bending.
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Unread 02-05-2016, 04:52 PM
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Re: 7075 sheet metal

Quote:
Originally Posted by GeeTwo View Post
Further, if I understand my research into aluminum grades a few months ago correctly, bending 7000 series (or 6000 series) aluminum with a tight radius disrupts the temper, greatly reducing the advantage of the aluminum grade unless you re-temper the piece. Many aluminum products with bends are made of 5052 for this reason; it has good strength without tempering and despite fairly tight bending.
That's sort of correct. You can't heat treat 5000 series aluminum, you can only strain harden it.
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Unread 02-05-2016, 07:56 PM
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Re: 7075 sheet metal

You never mentioned what temper the 7075 is. Might make a difference...

I found this bend radius table that shows workable bend radii for 7075 sheet products.

http://www.americanmachinetools.com/bend_radius.htm

We have found it easy to hit controlled bend radii on our pan and box brake by making forms out of very soft aluminum to put over the fingers on the brake. You could do the same, or use a press brake with a die of the appropriate radius.
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