It's an interesting question, and it prompted me to check my assorted SunTours.
I've got numbers from the 1st gen Cyclone (or at least I think it's 1st gen).

Some numbers:
parts: Bolt, nut, and two thin shims.
Bolt:
OD of unthreaded portion that fits in derailleur body: 11.97mm
OD of threaded portion: 9.79mm (that fits in M10 hole in hangar)
Length of unthreaded portion: 5.68mm
Length of threaded portion: 9.04mm

nut:
only two slots on the back to use for adjustment.
OD: 16.1mm
ID: 8.94mm
thickness: 4.13mm

and some pics:

the derailleur:




the bolt, nut, and shims:




and an example of one measurement.... the length of the unthreaded portion of the bolt.
fwiw, it was difficult to hold the caliper in one hand and the camera in the other, so the caliper isn't in exactly the right location for the photo.




Steve in Peoria