Method of fastening a wear plate and a knife base to a disc chipper, and a disc chipper

A disc chipper comprising:

• a plurality of knives;
• a rotatable disc on which the plurality of knives are mounted;
• a plurality of knife bases, a knife base of the plurality of knife bases being disposed under each knife of the plurality of knives;
• a wear plate arrangement disposed in sectors between the plurality of knives
• bolts for mounting the wear plate arrangement and the knife bases to the disc, the bolts extending into threaded openings in the knife bases and the wear plate arrangement and not extending through a front surface of the wear plate;
• the wear plate arrangement including counter surfaces in the form of grooves substantially parallel to corresponding ones of the plurality of knives, and each knife base including a counter surface in the form of a ridge for being received in a corresponding groove counter surface of the groove counter surfaces, the plurality of knife bases having a plurality of ridge counter surfaces;
• wherein, when the bolts are tightened, the wear plate presses the knife bases against the disc via the groove counter surfaces and the ridge counter surfaces.