8mm head
-DIN 6921-
M6 x 25mm 10.9
(used for clutch cover Vespa PX,
T5 125ccm, PK S, PK XL, PK XL2,
V50, V90, PV, ET3)
Although these are the modern equivalent of a clutch cover bolt they can be used in all older models

Whoever maintains and works on their scooter themselves should make sure a supply of suitable fastenings, gaskets, etc. are available in your workshop all times. What can be more annoying when being in the middle of a complete engine rebuild or similar to be stopped in your tracks by the lack of any particular nut or bolt?

OEM numbers (for comparison purposes only)
Piaggio AP8152280, S.31091, S31091, 414837, 30050,
31092
Aprilia AP8152280
Innocenti 70450620