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Tiny brass rivets, heads snapping off :(

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  • Tiny brass rivets, heads snapping off :(

    Hi people. I am trying to make some small brass rivets. Do I need to do anything to the brass before I start working with it to stop the rivet heads from chipping/snapping off?

    I have never worked with brass before. Maybe annealing it, or heat treating it in some way?

  • #2
    I only know enough about brass to be dangerous, as they say. The brittleness that is causing the heads to snap off is due to the fact that you are using a brass with too much zinc in it. (EDIT: should have said "may be due to"--the way I worded it sounded like I know for sure, and I don't ) See below.

    Alpha brass: <35% zinc and >65% copper
    Alpha-beta brass/Duplex brass: 35-35% zinc and 55-65% copper
    Beta brass: 45-50% zinc and 50-55% copper
    White brass: >50% zinc and <50% copper

    As the proportion of zinc in the alloy increases, the alloy loses its malleability and becomes brittle. Malleable varieties of brass can be worked upon, even when cold. As the brittleness increases, it becomes mandatory to heat the brasses before working upon them.

    This makes sense to me--think of pot metal--mostly zinc--really brittle stuff. What I don't know is how these categories relate to the commonly available brass materials that are usually defined by a number to represent the alloy--probably a half hour on google would answer that.

    If you look at MSC Industrial or McMaster-Carr, they sell it by alloy number: 260, 353, 360, 464. I think, but am not sure, that you want 260. My guess is that the workability is only while it's hot, so you would have to heat every rivet while peening it -- I don't think you can heat treat it like steel and change it's basic properties, but I'm not sure. Need someone with some metallurgy background to answer this.
    Last edited by Aeronca41; 08-25-2020, 09:15 AM. Reason: Correct statement


    • #3
      Peening is going to work-harden the brass, so annealing should help after forming the heads (and/or halfway-though forming the heads)...

      The necks of brass cartridge cases get work-hardened after several firings and re-sizings for the same reason, and annealing the necks with a propane torch after every 2-4 firings helps prevent neck cracking, FWIW.