Abstract: The present invention is related to a hub for a rotatable chair, said hub comprising an essentially pyramidal body having its side faces (1) suited for the mounting of the chair's leg element (2) thereon and further including a centrally aligned cylindrical cavity (3) suited for accommodating the center rod (4) of the chair seat cushion. The hub is characterized in that the lower part of each side face (1) is flared outwardly forming a slanting flank (5) with at least one hole (6) suited to accommodate a fixing screw (7) adapted to be screwed from underneath the hub into each leg element (2), and that each side face (1) further includes an essentially radially projecting support element (8) adapted for insertion into a mating groove (9) provided to each leg element (2).