Tightening torque and prestressing force

The following pages contain tables for a couple of commonly occurring tightening situations:

  • tightening torque for untreated, lubricated steel bolted joints and
  • tightening torque for waxed, stainless steel bolted joints.

In order to achieve the correct prestressing force, a torque wrench or a screwdriver/impact wrench with torque control is used. Torque variation max. ±5%.
In the event of other friction conditions, bolt or nut types, the values must be recalculated.
In those cases where high demands are placed on the bolted joint, e.g. if personal injury or a serious mechanical fault could arise as a result of a damaged bolted joint, the prestressing procedure and prestressing data must be determined through procedure tests.
For more information about tightening torques, prestressing force and procedure testing of bolted joints, please contact our technical support.

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Björn Malmqvist
bjorn.malmqvist@nfgab.se
+46 303 20 67 00