Actually those are two different types of nuts. On the left we have proper track nuts, on the right are serated nuts.

The serated edges do bite (chew) into the frame and should hold, though they can suck to tighten up as they can walk forward in the forkends.

The track nuts should hold just about as well but the base is actually a captured washer that doesn't rotate as you tighen down the nut, thus saving your dropouts/ends.