Never come across any of these before, they are quite stiff to get on and off just like a nylock. Was thinking some sort of alternative nylock for bits that get hot?
or do you think you would punch the lugs down after tightening ?
It's actually a version of a Simmonds nut - a self locking device which stems from another type, the pinnacle nut.
They work because during production it is threaded in the usual way but before sale the top couple of threads are distorted, hence giving a sort of cross threaded approach which causes self locking.
Simmonds also gave their name to nyloc nuts, and other types - small diameters of which are actually squashed oval to give the same effect.
John
