Dalboy
Established Member
It was the fact that the images were of Die NUTs which are generally used to repair damaged threads rather than manufacture from new so it is unusual to see them 'split' and fitted with what I imagine is a tapered grub-screw to make them adjustable. That is a very complex method and typical of 'Snap-On' to find a solution to a problem that didn't exist.
All those that i posted of the snap on are for cutting threads I do have some of snap on thread repair nots which are as you said are different. It may be a design that you may not have seen before.