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© 200423 1-1 Threaded connections THREADED CONNECTIONS ΧΦ75 series 2 1. THREADED CONNECTIONS 1.1 GENERAL The components may have threaded connections that have been treated with lubricant (dipped threaded connection). Galvanised bolts and nuts are wax dipped in the factory. Black annealed and phosphatised bolts and nuts are oil dipped. The advantage of using dipped nuts and bolts is that friction during tightening is reduced, so that the specified pre-tension force can be accurately obtained. The tightening torque can be reduced while the pre-tension force remains the same. To achieve a small spread in the pre-tension force, the dipped threaded connection must be tightened accurately. Therefore, always use a reliable torque wrench that provides a high degree of accuracy. Note: Have torque wrenches regularly inspected and calibrated. Re-use of fasteners (bolt/nut/threaded end) Clean the thread (take particular care to remove locking compound residues) and the clamping faces 2. Check the thread for damage. To do so, manually screw a new nut/bolt onto the thread to be checked. If the new nut/bolt cannot be fully hand- screwed onto the entire thread of the fastener to be checked, the fastener is not allowed to be re-used. 3. Apply one drop of engine oil to the upper turn of the bolt (threaded end)/lower turn of the nut and one drop to the clamping faces (other lubricants are not allowed). 4. If a locking compound has been specified, oil should not be applied to the thread. |