Socket screws are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or socket.#10-32 Socket Head Cap Screw, Plain Steel, 5/8 in Length, 10 PK A hex key is required to tighten or loosen a socket screw..
3/8"-16 x 9" Hot Dip Galvanized Grade 2 / A307 Steel Coarse Thread Carriage Bolts 50PK The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut is tightened..