ABSTRACT
Proper lubrication in an aluminum bolted joint cannot be emphasized enough. Figure 1 graphically shows the salutary effect of lubricant on clamping load relative to bolt tensile breaking load. If tightening torque is applied to the nut, the common practice is to use a bulk lubricated nut so that the threads and the bearing face are lubricated. Most commercially available nuts are waxed by the manufacturer, but the user should be certain this has been done. If the bolt is to be tightened, then arrangements will have to be made to have the commercially available bare aluminum bolt lubricated, which again is best done in a bulk method to be sure the threads and head bearing surfaces are lubricated.
