Bulk Carriage Bolts & Elevator Bolts
Round head square neck bolts are referred to as Carriage Bolts. With their trademark shallow, mushroom-shaped head, these bolts are intended to be used in low profile applications where access to installing and removing the bolt is only available from the nut side. This includes many wood-to-wood or metal-to-wood applications. Because of the 1-sided access, they are also often used in applications where tamperproof access is desired.