Abstract: The invention relates to a combination of two factory-built forms consisting of two form panels set within sectional steel frames having longitudinal channels with flanks forming an acute angle to each other and having outer flanges and ribs; in the locked and tightened state the ribs are in contact with each other; the combination also consists of a form lock device which forces the steel frames tightly against each other and brings the outer flanges into alignment.

Abstract: A steel section has a protuberance which rests on the outer circumferential surface of a framework panel concrete. A first short flange rests on the inner side of the panel. A second, long flange extends perpendicular to the framework panel and has a shallow V-shaped indentation. A third, short, flange lies parallel to the framework panel and a fourth flange continues to the protuberance. The third flange consists of two part-flanges butt-welded and flush-machined on the outer surface. The protuberance has three walls. The second, short, wall is parallel to the framework panel. The third wall is bent back to the first wall at an acute angle. The corner angle between the first flange and the third wall is less than 90 degrees.

Abstract: A pair of L-shaped claws consisting of longitudinal and cross members are substantially congruent, rigidly connected and spaced a short distance from each other. Two aligned elongated openings are provided in the center of each cross member, for receiving a vertically-oriented tensioning wedge. A third claw, substantially congruent with the first two claws is guided with its cross members longitudinally in the space between the first pair, with little play in the transverse directions. This third claw also has an elongated opening in its cross member for receiving the tensioning wedge. The cross sides of the first mentioned elongated openings which contact the tensioning wedge on one side is opposite to the cross side of the last mentioned elongated opening, which contacts the tensioning wedge on its opposite side. A contact surface for the frame piece is provided on the side of the cross members of claw pair, directed toward the outer leg of the frame piece.