I haven't seen this style nut before, and McMaster Carr doesn't even carry it. They are for use in the linkage of ITBs. Note there is a hole on the screw.

Does that flat side go on first? How exactly do I wire this hole?

Anyone seen these before?

-Steve

Click to view attachment

Click to view attachment

Click to view attachment

The hole in the bolt is for a "cotter" key to be used with a castlated(sp) nut. The nut you have is a lock nut used extensively in aircraft. You wouldn't normally use a cotter key with this type of nut. The flat side goes on first.

Thanks, got it. That makes sense to me. I'll just order some slotted nuts. I know what to do with those...

http://www.mcmaster.com/#slotted-nuts/=o5manm

-Steve

If that is an AN3- or AN4- bolt I have the castellated nuts and cotter pins. I'm in Temecula if you need a few.

yup - ovaled lock nut - nice ; )