The Hillman Group 3504 5/16-18 By 2-1/2-Inch Stainless Steel Carriage Bolt, 10-Pack Carriage bolts have a domed head that is not designed to be driven A bolt with a square shoulder under a rounded head which resists turning when the nut is tightened Stainless steels are used for their corrosion resistance, high-temperature strength, scaling resistance and low-temperature toughness Quantity per pack: 10