We see this question fairly regularly, and there's good news. We made it as simple as we could. We include the correct amount of screws (set screws too) for the length of bracket you purchase. So if you buy an 8-foot bracket, and want to use a 6-foot bracket and a 2-foot bracket for two different shelves, just use ¾ of the screws included for the 6-footer, and ¼ for the 2-footer. Easy as that!