Squeezing a -5 rivet

I have to replace a -4 rivet with a -5 one because of an oblong hole. Most of the specs I see for the cleaveland pneumatic squeezer and the main squeeze is that they will only squeeze up to -4 rivets. Anyone tried squeeze a -5?

have you tried the "puffy" shank trick on the -4?
(partial squeeze a longer rivet in the squeezer jaw, and then put in the hole and finish the squeeze). Trial and error to get the right length and "puff".
Otherwise you could solution heat treat the -5. They squeeze like butter before they age harden.

Thanks Mike, interesting ideas! When you say heat treat can you be more specific, i do have a nice furnace at my disposal

You can just buy a few soft rivets from Aircraft Spruce.
Just order the size you need but make sure you order the soft rivets. (e.g. AN426A-5-4 instead of AN426AD-5-4).
You can order small numbers by ordering .01 or .1 pounds and they are cheap.
FYI - a soft A rivet does not have the dimple in the head like a hard AD rivet has so they are easy to identify.

sf3543 said:

You can just buy a few soft rivets from Aircraft Spruce.
Just order the size you need but make sure you order the soft rivets. (e.g. AN426A-5-4 instead of AN426AD-5-4).
You can order small numbers by ordering .01 or .1 pounds and they are cheap.
FYI - a soft A rivet does not have the dimple in the head like a hard AD rivet has so they are easy to identify.

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Maybe one or two, but I wouldn't make a habit of using soft "A" rivets. They never get hard and are not very strong. (different alloy) In fact, it is probably stronger to over-squeeze an AD-4 rivet into the oblong hole than to use a soft A-5.

Or, as mentioned by fl-mike, it is better to solution-treat an AD-5 rivet, squeeze it while soft, and over several weeks, it will regain strength as it age-hardens.

tdavis1198 said:

Thanks Mike, interesting ideas! When you say heat treat can you be more specific, i do have a nice furnace at my disposal

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I hate to open this can of worms, but you need a very well controlled oven if you want to try this. I have done this for a few rivets, like if I had one in a difficult spot, but do not do this as a general practice. It is too easy to mess up the physical properties in ways you can't see.
https://materialsdata.nist.gov/bitstream/handle/11115/192/Heat%20Treating%20of%20Aluminum%20Alloys.pdf?sequence=3&isAllowed=y
Basically, subject the rivets to a temperature between 925? F to 945? F for approximately 30 minutes, and immediately quench in cold water. The rivets reach maximum strength about 9 days after being treated.

I've used '-4.5' oversized (9/64 shank) rivets for some cases where a 5 was too big. Problem is you have to buy by the pound

Thanks for the info Mike. I have a precision furnace so I can do this. I assume I do it on a A rivet as opposed to an AD rivet?

tdavis1198 said:

Thanks for the info Mike. I have a precision furnace so I can do this. I assume I do it on a A rivet as opposed to an AD rivet?

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AD (2117T4 alloy) i.e., the "regular" type.

You will be surprised at how soft they are after the quench. You can squeeze them with a pair of pliers. Check them again after a couple weeks and they should be back to "normal". Also, be advised that the coating will dissolve into the metal, so they will loose coloring.

Interesting thread. I certainly understand heat treating, but what is "solution-treating?"

Nevermid, googled it. lol

https://www.industrialheating.com/b...solution-heat-treatment-of-aluminum-fasteners

For my couple 5/32 rivets (oversized hole from drilling out) I used the rivet gun and bucking bar. Did have to buy a 5/32 cup set, but if using a squeeze you will need a 5/32 squeezer set.

tdavis1198 said:

Thanks for the info Mike. I have a precision furnace so I can do this. I assume I do it on a A rivet as opposed to an AD rivet?

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Please don't use 'A' rivets.

The point here is to soften an 'AD' rivet so it is easier to squeeze, in a way that it will recover its strength.

Age-hardening (also called precipitation hardening) of aluminum takes place as an alloying agent, copper in the case of 2000-series aluminum, precipitates out of the aluminum crystal solution. The random dispersal of copper atoms in the interstitial spaces in the crystal interfere with the movement of aluminum atoms as the crystal is strained. (actually it is minor defects in the crystal called dislocations that move, by making individual atoms adjust their position around the dislocation). By interfering with the movement of dislocations, it takes more force to move them. Thus the crystal is stronger.

When you solution-treat the aluminum, what you are doing is putting the copper atoms back into solution in the crystal. They take the place of aluminum atoms in the matrix and do not interfere with the movement of dislocations. So the material acts 'soft'.
Over time, the copper atoms precipitate out of the crystal again, regaining strength.

This process is quite different from annealing. Annealing is done at a temperature BELOW the solution treating temperature. Typically 750F for aluminum. It does not dissolve the copper atoms back into solution. What it does is allow the aluminum crystals to 'relax'. Internal stresses are released by aluminum atoms moving or adjusting their lattice linkages. Dislocations are reduced (*). The result is a soft, workable state that will stay that way. So, for example if you get 2024-O, it is annealed, and will stay soft and workable. Once it is formed into a part, it can then be solution treated and age-hardened, becoming 2024-T4. (T3 reaches the same state, but is an accelerated aging rather than natural aging)

(*) - I have always found this paradoxical -- that yielding is the result of movement of dislocations, which take far less force than simultaneously shearing a whole crystal along a lattice plane. So more dislocations should allow for more easy yielding. Yet crystals with an absence of dislocations, by being annealed, are softer. I think the yielding process in this case involves the creation of new dislocations.

In principle this process is fully reversible and can be repeated multiple times. However, each time the alloy is heated, or the longer it is heated, the crystals, or grains, can grow larger by absorbing adjoining crystals. Larger grain size can be associated with reduction of some properties, especially fatigue resistance. So it is not a good idea to do this multiple times to something. But doing it once to rivets is fine.