Abstract: A centrifugal separator having a rotating chamber with a material advancing structure within the chamber including a spirally shaped carrier vane arranged coaxially within the chamber and supported on a rotatable driving shaft driven in rotation at a speed different than the chamber with a spirally shaped wear plate supported on the vane having an outer edge radially outwardly of the vane with a mounting face extending radially alongside a radial face of the carrier vane and a mounting piece secured to the mounting face of the carrier vane with means securing the wear plate to the mounting piece such as bevelled radially facing circumferentially extending interlock surfaces between a channel of the wear plate and the mounting piece and a tangentially or circumferentially inserted locking element extending between the radial outer surface of the mounting piece or the carrier vane for carrying the wear plate so that it will not tilt on the carrier vane.