Wall pass-through bolts

Has anyone noticed the cap nuts missing from the large wall pass-through bolts placed through the wall of their TrailManor?

On the outside, these bolts have special heads -- round with two small holes for a tool that reminds me of one of those special keys needed to open the fuel fillers on a boat.

I found two of the cap nuts (with locking washers beneath) missing on the door side of our trailer.   Our one-year old found of the nuts (yikes!) but it appears the threads are torn as I it seems larger than the threads on the bolt exposed inside the trailer.

This doesn't seem to have had any effect on our trailer (yet) but I'll be calling the factory for some replacement specs ASAP.

Jon,
I suggest you check your local hardware store for a cap nut that has the plastic insert to prevent them from coming loose again.  If I remember correctly it is a 1/4" bolt was an SAE thread (may be 5/16&quot.  Take one of the original nuts with you to find the right size and thread count.  They usually cost 10-15 cents each at ACE or True-Value.

Thanks, Paul.   I finally had the trailer open tonight to take one of the remaining bolts to the local hardware store.   It's a 5/16" cap nut, coarse threads.

I bought two stainless steel nuts and washers, and secured the nuts (including the one I removed) with blue loctite.

... For some reason, I thought the bolt ends were exotic, but it turns out they're just hex-nut heads.   I don't know why I thought they were dot-holes.   Memory's the second thing to go.  Now, if I could only remember what was the first!