The Erickson Dock Cleat part # EM53501 for 4" long, part # EM53400 for 6" long, or part # EM53500 for 8" long uses a 5/16" hex head bolt. We do not offer this bolt nor does Erickson sell them as the length and finish will depend on your specific application. You can pick these bolts up from your local hardware store. view full answer...