Coefficient of friction

Illustrated explanation

Torque produces clamp load through friction and geometry

3Coefficient of friction
Torque produces clamp load through friction and geometryCallout 1: Turning moment. Callout 2: Joint preload. Callout 3: Friction. Callout 4: Anti-seize. A tightening moment creates joint preload indirectly. Friction and surface compounds change the relationship between the applied torque and resulting clamp load. Current term: Coefficient of friction, callout 3. 1Moment = force × lever armTurning moment 2Initial clamping forceJoint preload 3Surface pair + conditionFriction 4Anti-seize
  1. Torque

    The turning moment depends on force and lever arm. Apply the correct tool at the specified component and location.

  2. Joint preload

    Opposing arrows show the initial force holding mating surfaces together. Preload is a force, rather than the torque reading itself.

  3. Coefficient of frictionThis term

    Resistance to sliding depends on the surface pair and conditions. A friction change can alter preload at the same torque.

  4. Anti-seize compound

    The permitted surface compound helps control binding and disassembly. Use the specified torque procedure and protect restricted sealing or contact surfaces.

A tightening moment creates joint preload indirectly. Friction and surface compounds change the relationship between the applied torque and resulting clamp load.

Conceptual forces without torque coefficients or installation values. Use the model-specific procedure for the actual materials, coatings and lubrication.