These Forgefix High Tensile Hex Head Bolts are made from 8.8 grade steel. The bolts are part threaded and conform to DIN 933 standards. The hexagonal head has been designed for use with spanners or sockets and offers maximum torque when used with these tools. APPLICATION:For fastening together numerous types of material or to be fastened into pre-tapped holes. Widely used in many engineering applications. Zinc coatings prevent oxidation of the protected metal to create a longer lasting finish. It does this by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not trigger a breakdown of the substrate’s surface integrity Ref: UTTK14678