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Electrical resistance of flattened (smashed) wire?

  1. Oct 4, 2011 #1
    Can anyone tell me what happens to the electrical resistance of solid copper wire, i.e. #4 gauge, (about .21" in diameter) uninsulated solid copper wire when you flatten it, i.e. with a hammer?

    I'm going to insert that wire inside a piece 1 3/8" diameter copper pipe, and smash the pipe over the wire to try to spread out the mutual contact area as much as possible. The application (a homemade spot welder) requires as close to zero resistance as possible between that very short length of #4 wire and the 1 3/8" diameter pipe. (It's for 1.2 volts at about 1500 amps. The unsmashed end of the solid wire will be the electrode tip, and the 1 3/8" diameter pipe will be the electrical tong it connects to.)

    I just can't seem to figure out if the resistance of a copper conductor would increase or decrease when you mash it.

  2. jcsd
  3. Oct 5, 2011 #2


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    Gold Member

    #4 wire can carry 1500 amps? You sure about that?

    As far as smashing it, I don't think it would lesser or increase resistance.

    Area is area......in my opinion.
  4. Oct 5, 2011 #3


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    Staff: Mentor

    Even if workhardening copper does increase its resistance a tad, I reckon it will get well annealed during welding operations! :smile:
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