An inner tube for a telescopic steering column (8) is provided, with a first end sector (2) for assembling a bearing (9), having a substantially circular cross-section obtained by reducing and drawing, a second end sector (3) and an intermediate sector (4) having a regular polygonal section, provided with longitudinal planar external guiding faces (5), wherein the first end sector (2) comprises a plurality of external flanges (6) emerging longitudinally from its external surface (2a) in axial alignment with at least some of the external guiding faces (5), and a plurality of longitudinal internal recesses (7) penetrating its inner surface (2b), each internal recess (7) extending under one of the external flanges (6); each external flange (6) comprises an essentially planar external surface which is at least partially flush with the external guiding face (5) with which it is aligned.