OEM ring nuts are made from pure kwap. They are mostly made of plastic - and after a few years they swell up and can hardly be removed. This was confirmed to me by my local tire dealer, who regularly checks and changes the tires on my vehicle. They wanted to sell me a new set of nuts for about $45. I refused and took this. I have an "old" wrench that I used to replace 20 nuts one at a time. I had to use a hammer on 2 OEM nuts to mount the wrench! The new nuts were solid metal and fitted together perfectly. I don't expect any problems with this as long as I have a car.