For projects that require wood-to-wood connections, carriage bolts are the ideal choice. A carriage or coach bolt is distinguished from others by the shape of its head: a rounded head and a square shoulder, together, resist turning when the nuts tightened or removed. This particular shape makes the bolt self-locking when placed in a square or round hole, in most woods. Used for a variety of applications, from dock or deck construction to playgrounds, these bolts are ideal when a smooth finish is needed. Browse our extensive selection of bolt grades and sizes below.