A method for forming a joining profile in a structural member comprises providing an assembly having a base member, a forming body and a pair of side anvils having profiles formed therewithin. The method further comprises mounting the structural member on the base member, advancing the forming body toward the structural member such that the structural member is clamped to the base member, urging the side anvils toward flanges of the structural member, forming a profile in each of the flanges, and engaging protrusions of the side anvils with the web such that opposing portions of the web are forced upwardly by the protrusions at locations adjacent to each one of the flange profiles in order to accommodate formation of the flange profiles in the structural member. Formation of the joining profiles in the structural members allows for detachable engagement thereof with another member having a corresponding mating profile.