HEX CAP SCREWS
 ANSI B18.2.3.1M 1979
All Dimensions in Millimeters
Basic
Bolt
Dia.
Width Across Flats Width Across Corners Head Height Wrenching 
Height
Max. Min. Max. Min. Max. Min. Min.
M5-0.8 8.00 7.78 9.24 8.79 3.65 3.35 2.4
M6-1.0 10.00 9.78 11.55 11.05 4.15 3.65 2.8
M8-1.25 13.00 12.73 15.01 14.38 5.50 5.10 3.7
M10-1.5 16.00 15.73 18.48 17.77 6.63 6.17 4.5
M12-1.75 18.00 17.73 20.78 20.03 7.76 7.24 5.2
M14-2.0 21.00 20.67 24.25 23.35 9.09 8.51 6.2
M16-2.0 24.00 23.67 27.71 26.75 10.32 9.68 7.0
M20-2.5 30.00 29.16 34.64 32.95 12.88 12.12 8.8