Socket Flat Head Screw Head Type Flat System of Measurement Metric Drive Type Socket Drive Size 12 mm Material Steel Material Grade/Class Class 10.9 Finish Black Oxide Thread Size M20-2.5 Minimum Thread Length 40 mm Fastener Length 40 mm Head Height 8.5 mm Head Diameter 36 mm Pack Size Small Pack Thread Style Fully Threaded Special Features Not Applicable Countersink Angle 90 Degrees Dimensional Standards DIN 7991 Flange Diameter Not Applicable Flange Thickness Not Applicable