Start with the symptom
Play is lateral movement around the pivots. Tap usually describes the blade or trainer contacting the inside of a handle when the assembly is moved side to side. A knife can have some play without tap, and eliminating every trace of movement is not always a realistic or useful goal.
Check the simple causes first
- Confirm pivot and body hardware are present and undamaged.
- Check for dirt or debris around the pivots.
- Look for bent or damaged components after impacts.
- Compare both handles instead of assuming both need the same adjustment.
Adjust in small increments
For user-serviceable pivots, make small changes and test swing after each change. Over-tightening can bind a handle. If the knife uses fitted bushings, forcing the pivot tighter will not correct an incorrectly fitted component. Bearing systems have their own stack-up and cleanliness requirements.
When to stop
If adjustment produces binding, roughness, inconsistent swing, damaged screws or a problem that immediately returns, stop and identify the mechanical cause. Maker service or an experienced technician is preferable to removing material from precision parts without measurements.