# WQ - Wrench Quality

Tools
STwrench

Strategy used for the quality test of the tightening performed with the STwrench.

Parameter | Description
--- | ---
Control Strategy | The Wrench Quality strategy can be configured with the following control strategies. Residual Torque/Time: This strategy analyzes the torque trace as a function of time. The operator shall execute this operation with a single, steady, movement. The wrench automatically recognizes the breakaway and residual point. Residual Torque/Angle: This strategy evaluates the residual torque on a joint, looking for the residual point of the Torque/Angle trace. Residual Torque/Peak: This strategy evaluates the residual torque on a joint as the peak torque necessary to rotate the bolt further. Loose and Retighten: This strategy loosens a bolt and retightens it back to its original position Yield Point: With this strategy the wrench detects the yield point automatically. Target Angle specifies how far beyond the yield point the user may tighten.

Based on the control strategy selected, a combination of some of the parameters listed below will be displayed.

Parameters | Description
--- | ---
Ratchet time | Numerical value for ratchet time which is by default 5000 ms. This allows the operator to release the torque for a while and recharge during the tightening operation. If the Ratchet time is exceeded the result of the tightening is marked as NOK with the reason "Tightening timeout".
Torque correction coefficient | The parameter is used to correct the torque reading when using an extension or torque multiplier on the wrench. Default value is 1.
Angle correction | The parameter is used to correct the angle reading when using an extension or torque multiplier on the wrench. Default value is 0.
Target Angle | Defines the target angle for tightening step.
Rehit detection | On or Off. Rehit detection can be used to determine when a tightening is a rehit based on the angle limit setting. Angle limit for rehit is enabled if Rehit direction is set to On.
Linear slope coefficient | Linear slope coefficient characterizes the joint stiffness in the linear part of the curve, as torque/angle slope in the Nm/Deg measurement unit.