M3 M4 M5 M6 A2 Stainless Steel Allen Bolts Socket Cap Screws Hex Head DIN912
Standard: DIN912. M3 M4 M5 M6 Socket Cap Screws A2 Stainless DIN914. They are tightened using a hexagon wrench. Socket Screws. They are fastened with the use of screwdriver with hexagonal insert bits or simply using an Allen key.