BBI Carriage Bolt, Fully Threaded, Measurement System: Imperial, 1/2-13 Thread, 3 in Length Under Head, Medium Carbon Steel, #5 Grade, Zinc CR+3, 1.094 in Diameter Head, 0.281 in Neck, Square Neck, 60000 psi Tensile Strength, 0.515 in Drive, UNC Thread, Square Drive, B70 to B100 Hardness, Round Head