Exhaust primary stud size

[nic.day]

Just re fitting the newly wrapped primaries to the engine - last bolt = lost!!! for the life of me I cannot find it. It dropped somewhere and I have looked and looked, tried the extending magnet etc etc. no luck

So what is the size of nut I need to get? - I am not taking any of the others off as they are a pain in the ar$e 

R500K to help

thanks

[oilyhands]

M10 x 1.5 flange nut, I keep them in stock, the rearmost stud is often replaced with an M10 x 30mm socket headed capscrew rather than a stud and nut. Studs are M10 x 1.5  x 35mm.

Oily