M39 Hex Head Bolts DIN 931 (ISO 4014) in Bright Zinc Plated (BZP) Class 8 High Tensile Steel

The most common type of fastener, a hex head bolt is designed to be tightened with a standard spanner or ratchet and socket. Popularly used in all assemblies, a standard hex bolt is a staple across the world. Manufactured to ISO 4014 or DIN 931, and therefore includes an unthreaded section of the shaft. A hex drive permits a greater torque load to be applied to the joint over most other drive types. Please note that due to manufacturing limitations, all nylon variants of these items are only "similar to" and not "in absolute accordance with" the standard specified.