STwrench User Guide Appendix A – Calculating correction coefficients for extensions
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Warning: The torque correction coefficient alters the STwrench torque measurement; a wrong
value of this coefficient may cause an improper torque reading, generating the risk of executing
a tightening at a different target torque to the one expected. Ensure you have calculated the
proper value when a wrench extension is used. For end-fitting tools used without wrench
extensions, the torque correction coefficient must be left set to 1.
Warning: When using an extension, the torque reading is affected by the hand positioning.
Always place the hand on the middle of the handle of the STwrench:
If a torque multiplier is used on the STwrench, the Torque Correction Coefficient must be set equal to the
torque multiplying coefficient of the torque multiplier.
Torque Correction Coefficient =
In the example of figure above, the proper value is 80/10 = 8.
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