Allen Hex Drive Size:M6x8mm(0.31") Screw Length: 8mm (excluding the height of the head); Thread Coverage: Full Thread Diameter of the head: 10.3mm (max); Height of the head: 3.3mm (max); Thread Pitch: 1mm; Exterior Finish: Bright/ Steel; Color: Silver Tone Made of Stainless Steel 304 (18-8) which is superior to regular steel and any zinc plated fasteners, provides good strength and corrosion resistance in bad environments Button head socket cap screws are precision threaded fasteners with an internal socket drive (also called allen hex drive) for installing in areas with limited side clearance. The internal hex drive requires an Allen wrench. They are known for their efficient application performance and endurance widely used in a variety of industries such as construction, manufacturing, engineering, assembling, aircraft and so on.