Bolted joints in SMC-R18 sheet molding compound composites were studied with the goal of determining joint proportions that provide long fatigue lives. The joint parameters considered were the edge margin in terms of the (e/d) ratio (where e is the edge margin and d is the hole parameter), the lateral pitch in terms of the (w/d) ratio (where w is the specimen width) and the washer geometry. It was observed that (e/d) should be at least three, and the lateral pitch should be at least six to eight to assure a fatigue failure originating at the edge of the washer. Smaller margins lead to bearing failures almost immediately or to splitting failures at relatively short fatigue lives. It was also observed that washer geometry (larger diameter) can lead to significantly longer fatigue lives.