M8 screw and bolt sizes for the more common ones we deal with. This will give information about the maximum screw head heights and head diameters as well as the driver size needed to install or remove them. If unfamiliar with DIN and ISO numbers, they can be thought of as exact fastener names for each specific screw and are usually given as either DIN or ISO (eg. DIN 912 or ISO 7380).M8 Screw and Bolt SizesMetric M8-1.25, Coarse Thread 

Type DIN ISO

Head Height

Head Diameter Drive Size
M8 Hex Bolts (FT) 933 4017 5.45mm 14.38mm* 13mm
M8 Hex Bolts (PT) 931 4014 5.45mm 14.38mm* 13mm
M8 Socket Head Cap 912 4762 8.0mm 13.27mm 6mm
M8 Low Head Socket Cap 7984 N/A 5.0mm 13.0mm 5mm
M8 Button Head Cap 9427 7380 4.4mm 14.0mm 5mm
M8 Flat Head Socket Cap 7991 10642 4.96mm 17.92mm 5mm
M8 Phil '+' Flat Head 965   4.0mm 14.5mm #3 Phil
M8 Phil '+' Pan Head 7985 7045 6.15mm 16.0mm #4 Phil

All of these will take a matching M8 Nut and Washer
Note: PT / FT = Partial Thread / Full Thread

* 'Width Across Flats' measurement given