Assembly for coupling wear parts to support tools for heavy-construction machinery

Assembly for coupling wear parts on tool holders for civil engineering machines comprising a tooth and an adapter with a keyed connection having bearing profiled matching shapes in different planes, located between respective contact and connecting ends, the matching shapes are arranged symmetrically and opposably on upper and lower faces of a nose of the adapter and of the tooth, and the bearing profiled matching shapes comprise staged shapes in different staged planes located between respective ends defined by a stabilization flat for the adapter nose and a root, for the tooth, and opposite connecting and centering ends, and said staged shapes present on the upper and lower faces of the adapter nose are established in prolongation of the stabilization flat and include an inclined plane extending from a plane of a first portion of the stabilization flat up to a connection with an upper part connecting the adapter nose to an adapter body, and a matching upper bearing plane which is angularly oriented with respect to the plane of the first portion of the stabilization flat and with respect to the inclined plane.