Abstract: A trenching wheel more especially for digging trenches, of the type in which the tools are mounted on ring portions removably fixed to the periphery of said wheel. The arrangement for fixing each ring portion to the periphery of said wheel include:a first assembly of two end faces provided respectively at the ends of said ring portiona second assembly of two abutment faces fixed to the periphery of said wheel and orthogonal to the plane thereof; anda wedge shaped key insertable from outside the periphery of said wheel inwardly thereof, between an end face of said first assembly and an abutment face of said second assembly for applying the other of said end faces of said first assembly under pressure against the other of said abutment faces of said second assembly.