DIN912 hexagon socket head cap bolt, also called allen cap screw. Cylindrical cap head with internal hexagon socket, tightened by allen key. Compact head design allows flush countersunk installation and delivers high clamping torque. Carbon steel grade 8.8,10.9,12.9 or stainless steel A2/A4. Surface: black oxide, zinc plated, HDG. Sizes M2~M20. Widely used for mould, machinery and precision equipment assembly.