1. A method for generating tracing information for solid objects, manufactured through the steps of: providing an unrefined piece; subjecting the unrefined piece to a plurality of transformation steps so as to obtain the solid object with the desired shape and material characteristics, wherein said transformation steps comprise one or more heat treatment steps that modify the mechanical characteristics of the piece, subjecting the unrefined piece or the solid object obtained from it to at least one control step for identifying pieces whose characteristics do not correspond to predetermined target characteristics, in which said method further comprises the steps of: equipping the unrefined piece, before said heat treatment steps, with a permanent individual marking having an encoding field with areas in bas-relief in said unrefined piece, that comprises an identification code of the single piece and that permanently identifies the single unrefined piece and the single solid object obtained therefrom during manufacture, reading the individual marking applied to the unrefined piece and storing the read identification code in a database, identifying, during at least one of the heat treatment steps or during said control step, the identification code of the piece or of the solid object obtained from it by reading the individual marking and associating one or more process parameters of said heat treatment step or a result of said control step with said identification code, storing said process parameters of said heat treatment step or said result of said control step and the association with said read identification code in the database.