Calibrating Torque Wrenches According to ISO 6789
DIN ISO 6789 names the requirements and the test procedures for handheld torque tools which allow controlled fastening at bolted joints. Torque wrenches are classified regarding type and measuring range with a tolerance of 4 % resp. 6 %. Calibration must be undertaken after every 5,000 measurements and the measurement uncertainty of the calibration unit may only be max. 1 % of the reading.