d1 for screw size d2 s 2.1 M2 4.4 0.5 2.6 M2.5 5.1 0.6 3.1 M3 6.2 0.8 3.6 M3.5 6.7 0.8 4.1 M4 7.6 .09 5.1 M5 9.2 1.2 6.1 M6 11.8 1.6 8.1 M8 14.8 2 10.2 M10 18.1 2.2 12.2 M12 21.1 2.5 14.2 M14 24.1 3 16.2 M16 27.4 3.5 18.2 M18 29.4 3.5 20.2 M20 33.6 4 22.5 M22 35.9 4 24.5 M24 40 5 27.5 M27 43 5 30.5 M30 48.2 6 33.5 M33 55.2 6 36.5 M36 58.2 6 39 M38 61.2 6 42.5 M42 68.2 7 45.5 M45 71.2 7 49 M48 75 7 53 M52 86 8