Tubular fold-away legs for support surfaces which includes a joint, which is made up of an element for coupling to the tubular body and an attachment element to said support surface, the legs being mobile between a first closed non-operative position and a second open operative position, tilted by an angle with respect to the support surface. The joint is equipped with elastic locking device to secure it in either the non-operative or operative positions and with a stable attachment device when in the operative position, as well as matching tilted centering surfaces.