Difference is Vlads are a good 1/2mm plus thinner than design min thickness, the wear rate isn't linear and accelerates when thinner......
Some of the heat treatments can either involve firing or immersing in molten salt for a while, whichever method the hardening is obviously crunchy on the outside and soft on the inside.......armadillo!
Sorry back on topic....
They've done incredibly well....they need replacing.....they don't last for ever