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Torque to strip hex wrenches

  1. Oct 15, 2007 #1
    I have done mechanical testing on a set screw with a 4mm hex and its driver. I now have a set screw with a 3mm hex. Without the time and expense of making parts and testing, I want to know the percentage decrease in maximum torque that the set screw and/or driver will be able to withstand on the 3mm hex. I am getting a torque limiting device and I need it to be used for both set screws and I don't want it to strip the hex on the 3mm driver by being too large of a value.

    If the materials and hex depth do not change (only change is 4mm to 3mm hex), what decrease do I expect to see in the 3mm hex?

  2. jcsd
  3. Oct 26, 2007 #2
    If I understand your question correctly, you should use about 40% of the 4 mm torque when tightening the 3 mm screw.
  4. Nov 14, 2007 #3
    How did you get 40%

    How did you get to 40%?
  5. Nov 14, 2007 #4


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