# How to Calculate the Angle Correction

When a wrench extension is used, the Angle Correction allows linear compensation of the extension torsion based on the torque applied. The correction value is expressed in degrees at the smartHEAD Max torque.

1. On the Power Focus, configure a Torque (Control) / Angle (Monitor) tightening program with the following values:

   - Rundown complete torque = smartHEAD Min torque value (5% of smartHEAD Max torque)

   - Final angle monitoring torque = Rundown complete torque

   - Target torque = 75% of smartHEAD Max torque

2. Do three tightenings at 75% of the smartHEAD Max torque.

3. For each torque and angle value measured, do the following calculation:

   Angle correction = Angle measured x (smartHEAD Max torque - smartHEAD Min torque) / (Torque measured - smartHEAD Min torque)

4. Make sure the minimum and maximum angle values calculated do not differ by more than 10% of the maximum value calculated:

   Angle correctionmax - Angle correctionmin ≤ Angle correctionmax / 10

   If they differ by more than 10%, repeat the procedure from the beginning.

5. Average the three angle values calculated to obtain the Angle correction.

When a torque multiplier is used on the STRwrench, the Angle correction value must be left to zero; in this case the STRwrench cannot compensate the angle measurement.