M8 SHCS: Zinc finish Socket head cap screw M8x 1.25 pitch, uses M6 allen wrench to tighten/loosen. The nut size is M8, which uses a 13mm wrench/socket to adjust. These bolts typically used on wheel hubs as pinch bolts, bearing cassettes, disk carriers for sprockets and brakes as pinch bolts.
*To determine the length of a Flat head bolt, please measure the entire bolt including the head in millimeters