Place to get soft aluminum rivets?

I've been working on a project that involves lots of hand-peening of aluminum
round-headed rivets. I just ran through the first batch that were great
(uncoated, soft as cheese), but when I went into the second batch I hit a snag.
They're anodized, and whatever alloy the metal itself is, it's rock hard. I got
all these aircraft surplus years ago and have no idea where to go now. From
what I've found, the coated hard rivets are more common.
GTO(John)
Reply to
GTO69RA4
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You want AN470A rivets. Aircraft Spruce has'em for about $20 a pound. A pound is lots of rivets.
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If picking up surplus rivets, look for rivets with no head markings. Those are the soft ones. A dimple, two dimples, a raised circle, or triangle in the center of the head means the rivet is harder.
Dash numbers signify diameter and length.
Dale
Reply to
Dale Scroggins
Soot your rivets with an acet flame. Heat them until the soot just burns off. They will then be as soft as they will ever get, with the added bonus of getting hard again later, as they sit. Do them in batches that you can use in short order (like whithin an hour or so) or store them in a freezer to extend the work time.
If you want to buy cheese soft rivets, talk to an aircraft rivet supplier an ask for 1100 rivets (thats pure aluminum). 2117 or AD rivets have a single dimple, and are a little harder to set, but are very much the common aircraft rivet.
Cheers Trevor Jones
Reply to
Trevor Jones
Some aircraft rivets are supplied in buckets of dry ice to keep them soft, once they hit room temperature they start to harden up. Scrap lots of these are just that, scrap, they can't be softened up and once hardened, they can't be driven. Aircraft Spruce is one source of known-quality rivets, but not at scrap prices. If you're doing a lot of riveting, you might want to invest in a a pneumatic driver and some backing bars, they have those, too. They're online.
Stan
Reply to
Stan Schaefer
Spaenaur sells solid rivets.
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Brian
Reply to
Brian
Hmm, must be what, 20% copper?
(Ya, I've been reading up on phase diagrams and made a bar of 50/50 Al/Cu master alloy today to harden some aluminum wire. 201 alloy, anyone?)
Would seem to me you can cook them at 900°F or so to get the hard stuff back in solution, then quench in something, um... freon, nitrogen? If they age harden practically on reaching room temperature, I suspect you'll want it very cold very fast..
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams
Thanks for the info, guys. I'll check out those places. I've probably had these in boxes since the '70s, so I'm assured that nothing's been stored at a special temperature for a while.
The soft ones were just plain aluminum with no head markings. The hard ones are gold anodized or otherwise coated and have two dashes across the top of the head. Very hard and brittle. I suppose these were to have been kept in a controlled environment?
GTO(John)
Reply to
GTO69RA4
1100 alloy
The hard ones are
2024 alloy
Ted
Reply to
Ted Edwards
I've never read of anyone trying to reverse age hardening in rivets, would you want to bet your life on the results in an aircraft?
Stan
Reply to
Stan Schaefer
Heh, no, but no one said the OP was building a plane. (Although, if they smoothly expand in place then harden soon after, I don't see why they wouldn't be worse than the originals. Don't got a mile-long paper trail on 'em though.)
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams

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