The invention relates to a screwed sectional steel frame (1) wherein the ends (31, 32) of frame sections (16, 17) for lateral frames (2) are unsymmetrical and have miter edges (25, 26). On one end (31), an inwardly cranked fastening lug (18) projecting from the miter edge (25) is provided with openings (19) for fastening screws (39). The first end (31) is further provided with an insertion tongue (27) and the other end (32) is provided with a slot (28) for an insertion tongue (27) of a subsequent frame section (17). In order to link two frame sections (2), crossbars (3) are provided. These crossbars have on both ends inwardly cranked fastening lugs (21, 22) that are destined to rest on the frame sections (16, 17). The fastening lugs have openings (19, 23) with passages (20, 24) for self-threaded fastening screws (39) that extend through sunk-in through-openings (40) of the frame sections (16, 17).