Offshore metal drilling riser section comprising: - an offshore metal drilling riser section tube having a first end and a second end; - a first metal riser flange that is mechanically joined to the first end of the offshore metal drilling riser section tube, forming a first mechanical joining; and - a second metal riser flange that is mechanically joined to the second end of the offshore metal drilling riser section tube, forming a second mechanical joining; wherein the offshore metal drilling riser section is capable of withstanding dynamic loads exerted by an offshore drilling rig and a body of water in which the offshore metal drilling riser section is suspended, based on: - the offshore metal drilling riser section tube is consisting of an aluminum alloy; - the metal riser flanges are adapted to coupling a plurality of offshore metal drilling riser sections serially end-to-end; and - the first and the second mechanical joinings are non-welded; wherein the metal riser flanges, of the first and the second mechanical joinings respectively, are secured by threads over the offshore metal drilling riser section tube, wherein the threads are selected from the group consisting of: a taper, buttress, and breech thread, characterized in that at least one of the following aspects is also provided: (i) the offshore metal drilling riser section tube is composed of variable wall thicknesses along the length so that the offshore metal drilling riser section tube is thicker at the ends where the mechanical joints are located; and/or (ii) wherein the offshore metal drilling riser section tube further comprises: - a first offshore metal drilling riser section tube part; and - a second offshore metal drilling riser section part, wherein the first offshore metal drilling riser section tube part is joined to the second offshore metal drilling riser section part by a third non-welded mechanical joining so as to result in the offshore metal drilling riser section tube. - an offshore metal drilling riser section tube having a first end and a second end; - a first metal riser flange that is mechanically joined to the first end of the offshore metal drilling riser section tube, forming a first mechanical joining; and - a second metal riser flange that is mechanically joined to the second end of the offshore metal drilling riser section tube, forming a second mechanical joining; - the offshore metal drilling riser section tube is consisting of an aluminum alloy; - the metal riser flanges are adapted to coupling a plurality of offshore metal drilling riser sections serially end-to-end; and - the first and the second mechanical joinings are non-welded; (i) the offshore metal drilling riser section tube is composed of variable wall thicknesses along the length so that the offshore metal drilling riser section tube is thicker at the ends where the mechanical joints are located; and/or (ii) wherein the offshore metal drilling riser section tube further comprises: - a first offshore metal drilling riser section tube part; and - a second offshore metal drilling riser section part, wherein the first offshore metal drilling riser section tube part is joined to the second offshore metal drilling riser section part by a third non-welded mechanical joining so as to result in the offshore metal drilling riser section tube. - a first offshore metal drilling riser section tube part; and - a second offshore metal drilling riser section part,