Hello,
I need a few strange nuts like so:

My question is does this kind of thing already? The reason I ask is because in my head some distant memory is triggered and I think I may be able to get these commercially rather than make them. It reminds me of the kind of fixings one gets with flat pack furniture but I do not have any to hand to compare and do not know what they would be called. Bit of a long shot but worth a try.
It is to go both on the end of a push rod and a fixed bar for a contraption I am making.
Cheers