Originally Posted by lawsonmitchell
What about the ones Beneteau uses
+1 on not using a non-metric prop. The correct solution to your problem is to use the right prop. Anything else is a band-aide.
Regarding the Beneteau prop nuts; these are not standard prop nuts and require a special washer to secure the prop and nut. It does not use a cotter pin. You could use this nut, but why? They are not superior to the usual double nut and cotter pin setup.
I find it hard to believe that you cannot find a metric-bore prop and the nuts to go with it. These are not uncommon items and any prop shop worth its salt should be able to provide them with no trouble.