Aviation snips aka metal shears. What grit to finish sharpening at?

[jztam]

Hey Sharpening Folk,
Just wondering if leaving a toothy finish (320 grit) on metal shears is advised or should I finish at a super fine grit (1000 grit). Use case would be my car mechanic cutting sheet metal for brackets and shims.

 

[Frank Niro]

If you are seeing a "ratty" edge I suggest to maintain thickness integrity you go finer.
Frank