The Master Cylinder
Well-known member
This link is a cowling safety pin example:
https://www.aircraftspruce.com/cata...rganic&utm_campaign=shopping&utm_term=AN416-2
The AN416-1 is the largest one with .051" wire size. There not as big as the average wheel hub cotter pin but they would work. For smaller bolts they fit better.
McMaster-Carr has those too. https://www.mcmaster.com/products/cotter-pins/long-life-wire-snap-cotter-pins~~/