When a Bolt Pretension load is applied, the Mechanical application reports the following reactions:

Adjustment: This represents the displacement that occurs from the applied pretension measured at the point where the bolt is sliced. In Mechanical APDL terms, this is the displacement reported from the pretension node. This result is also available for reporting regardless of how the bolt is defined.

Working Load/Preload Reaction: This represents a constrained force reaction from the pretension load. It is the reaction from the applied constraint when a bolt is either specified as Locked, Adjustment, or Increment, and reports a zero value during a step in which you have applied the preload (since there is no reaction at the bolt slice during preload step). In Mechanical APDL terms, this is the constrained reaction reported from the pretension node. This is essentially the sum of all the forces acting through the pretension cut. This result is only applicable for load steps when the load is defined by either Locked or Adjustment or Increment.