Abstract: A freestanding stair assembly which is simple and chemical to produce and assemble is disclosed. The assembly utilizes a plurality of interengagable tubular links each of which is provided with pair of axially directed parallel slots in the annular wall. The slots extend from one end of the link and are oriented and dimensioned so as to receive therein the other end of a superjacent link. The links may be rotated relative to each other to achieve a linear or a non-linear stairway. Each link is adapted to have a stair tread member secured thereto. Also each main slot may be provided with a locking slot in the annular wall which is perpendicular to the main slot. Each riser may than have a lower flange at the other end, which flange can engage with the locking slots as relative rotation of the risers is performed. The circumferential extent of the lower flange is such that adjacent risers are locked together thereby at any reasonable relative angular orientation.