Screen cylinder with improved slot width protection and method of removing solid contaminants from a solid suspension

A screen cylinder comprising:

• a plurality of profiled bars aligned longitudinally and coupled to at least one support ring at attachment ends of the plurality of profiled bars, each of the plurality of profiled bars comprising:
• an outer surface facing away from the at least one support ring;
• a first slot surface extending from the outer surface to the attachment end of the profiled bar opposite the outer surface;
• a second slot surface opposite the first slot surface and extending from the outer surface to the attachment end of the profiled bar, wherein the first slot surface of one profiled bar and the second slot surface of another immediately adjacent profiled bar define a slot;
• and
• a hardened layer disposed on at least a portion of the first slot surface of the profiled bar, the hardened layer having a Vickers hardness value greater than or equal to 500HV0.05, as determined in accordance with ASTM E384-11e1, wherein the hardened layer is disposed directly on at least a portion of the first slot surface of the profiled bar and the hardened layer is an outer layer.