Supacheap Bolts Hexagon Head Class 4.6 bolts are manufactured to Australian standard 1111 and the bright zinc plated finish offers corrosion protection, suitable for general purpose internal and external bolting applications. Our Hot dipped galvanised finish bolts offer maximum corrosion protection and are suitable for general purpose internal and external bolting and can be use in treated timbers. Supacheap Bolts currently stock M6, M8, M10, M12 and M16 diameter bolts up to 400mm in length for certain diameters. Please note : Our Image is of a generic standard bolt and nut and thread lengths vary slightly per size so check with us before ordering if this dimension is of importance. Typically, thread lengths for our hex bolts will be to the recognised international metric standard. All bolt lengths are measured from under the head.