Plow bolts feature a countersunk, flat head, square neck, and unified thread pitch. They are used in road graders, scoop shovels, and other heavy-duty industrial equipment where a flat, smooth surface is required. Zinc plated fasteners have good corrosion resistant qualities. Grade-5 plow bolts are made from a medium carbon steel. Tensile strength: up to 1" - 120,000 p.s.i. (min). Three radial bars head marking.