Metric socket button head screws BS 4168 ISO 7380 Materials and Finishes Steel 10.9/Self colour Stainless steel/Self colour Dimensions d M3 M4 M5 M6 M8 M10 M12 Max D 5.7 7.6 9.5 10.5 14 17.5 21 Max H 1.65 2.2 2.75 3.3 4.4 5.5 6.6 2 2.5 3 4 5 6 8 1.04 1.3 1.56 2.08 2.6 3.12 4.16 S (key size) t min