Everbilt 5/16 in.-18 x 5 in. Zinc Plated Carriage Bolt (25-Pack)

Carriage bolts have a smooth rounded head with a square neck underneath that locks into wood when tightened. Use with a pre-drilled hole and secure with a hex nut and washer to prevent spinning. They are great fasteners for decks, play equipment, docks, fencing, and furniture.