They were used on Cub Campers at least till late 2011 on the adjustment feet for the floor. Should the dreaded iron oxide form on the adjustment bolts then too much force will cause them to spin in the channel. It would seem that Cub have overcome the problem and now sell a replacement part, a piece of steel maybe 8 to 10 mm thick and threaded. Having used these blind nuts in an earlier life I would suggest that they are OK for situations where they are not subject to rust or constant use. I am still removing them from my recently purchased Cub, a 2011 Daintree, but I still love it.