Product code
Standard 5.2.
Version
10650522 000
Tightening with torque wrench
1. Using a torque wrench, apply the pre-torque MAF as specified in the "Table of tightening torques" for the respective screwdriving condition. 2. Apply a mark on the screw head that is aligned with a mark applied on the component (see figure 4). 3. Apply a third mark on the component, which indicates the additional angle of rotation ΔΘ specified in the "Table of tightening torques" for the screwdriving condition marked in the drawing. 4. Using a suitable wrench (torque or standard wrench), turn the screw so that mark 1 and mark 3 are aligned (see figure 5). Figure 4
Marks on screw and component after application of pre-torque
Figure 5
Marks on screw and component turning by additional angle of rotation
Direction of rotation
5.3. Tightening with electric or hydraulic wrench 1. In the control program of the electric or hydraulic wrench, enter the values for pre-torque MAF, additional angle of rotation ΔΘ and the tolerance window for the additional angle of rotation and the final tightening torque. The values are indicated for each screwdriving condition in the "Table of tightening torques". 2. Turn the screws by hand or with a pneumatic wrench. When using a pneumatic wrench, ensure that the skews are only turned, i.e. that the torque of the pneumatic wrench is smaller than the pretorque! 3. Place the electric or hydraulic wrench on the screw head. Ensure that the reaction arm is suitably positioned. 4. Start the 2-step tightening procedure. 5. Check the achieved result (screw connection OK or NOK), indicated at the wrench tool. 6. Record the values of the achieved tightening torque and the additional angle of rotation. 7. After tightening of all screw connections, test a number of screws using the tightening torque according to LH standard 10409969. The number of screws to be tested depends on the total number of screw connections and is normally between 1 and 3 (see also section 6).
6.
Checking during routine maintenance 1.30.3