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Tube steel strength - advice on project

  1. Jun 12, 2015 #1
    Greetings, may I ask for a bit of help with a steel fabrication project?

    Pictured below is my design for a trailer-hitch mount to be used with a Harbor Freight tire changing tool.

    I need help determining the thickness and composition of the tube and plate steel to be used in the project. I don't want the mount to be damaged by the force of operating the tool. Note the inset picture; lifting the tire bead over the edge of the rim can require 100# of radial force on the 36" lever.

    I'd appreciate it if someone could review my design and offer improvements (or reductions) as necessary.

    Thank you.

  2. jcsd
  3. Jun 12, 2015 #2


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    Gold Member

    Welcome to the forum.

    Asking for a design review of a thing of this nature is a troublesome request. If you or one of your clients get injured, I don't want to be involved. I would suggest that such a review should not be performed for free. But hey, my second favorite race in Star Trek are the Ferengi.

    When building things like this it is often easier to start with a prototype. Build one and see what causes it to break. Calculating the required thickness and strength can actually take a long time, and not be very accurate without quite a lot of measurements. So set up a test rig to see how much force is really involved, and at what point various components begin to fail.

    Do be aware of the possibility that over-loaded metal will fail suddenly. And be aware that stressed metal can spring back or hurl shrapnel when it fails. So take all due precautions.
  4. Jun 12, 2015 #3


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    IMO... This is pretty good stuff... I welded lots of 4130 aircraft tubing, when I went through A&P school.

    Rule of Acquisition # 59 - "Free advice is seldom cheap"... :approve:

    Lol... :oldwink:
    Last edited: Jun 12, 2015
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