M1.6 - M20 Allen Key Countersunk Bolts Socket Screws Black Steel 12.9 DIN 7991
Thread Dia : M1.6 M2 M2.5 M3 M4 M5 M6 M8 M10 M12 M16 M20. 【Material】：Hex socket flat head bolts and nuts set are made of 12.9 grade carbon steel with black plated. - Material: 12.9 Carbon Steel.