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Tightening torque requirement for screws with washers

  1. Oct 20, 2013 #1
    Does the use of one or more flat washers change the required tightening torque of e.g. a M4 socket head cap screw?
  2. jcsd
  3. Oct 20, 2013 #2


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    Washers serve multiple purposes - as spacers, to distribute the load across the material, to keep nuts tight (lock washers), etc.

    But the torque is primarily determined by the threads and their contact. I don't see that the washer would affect this, but for special applications you could test this - such as structural bolts.

    But for ordinary things you can just follow the recommended torque tables.

    For example: http://www.portlandbolt.com/technicalinformation/bolt-torque-chart.html
  4. Oct 20, 2013 #3


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