Common M8 Fastener Screw and Bolt Sizes - MonsterBolts
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).
Metric 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