UNC Grade 8 High Tensile Hex Head Set Screws (Full Thread) are supplied with a spring washer & high tensile flat washer. The included washers are supplied at no extra cost. Supacheap Bolts Hexagon Head Grade 8 UNC High Tensile Set Screws are manufactured to Australian Standard 2465 and our bright zinc plated finish offers corrosion protection and are suitable for general purpose higher strength internal and external bolting where maximum adjustment may be needed, and for fastening blind threaded components where a thread, running the full length of the bolt, is required. Typical applications for this very widely used product include steel fabricators, machine builders, automotive applications and the mining and construction industries. Supacheap Bolts currently stock 1/2" and 5/8" diameter set screws up to 2" in length for certain diameters. Please note: Our Image is of a generic standard hexagon head set screw and the length of a set screw is measured from under the head.