A structural screw jack capable of easily accommodating adjustment of its
angle of inclination. The screw jack can allow the orientation of a chute located at one end of the screw jack is be adjusted to define either a right angle to the longitudinal axis of the jack, or over a range of oblique angles relative to its longitudinal axis so that the screw jack may be installed at an
oblique angle between earlier installed vertical and horizontal oriented structural steel shapes, and thereby enabling a reduction in the number of process steps customarily used during field installation of
diagonal braces supported by a screw jack. The screw jack includes a lower
coupling shaft, a lower jack, and a
steel bar. The upper jack includes an upper
coupling pipe having a plurality of reinforcing ribs formed on the outer side surface thereof, and an upper holder closely coupled to the outer side surface of the upper
coupling. One end of the lower coupling shaft is integrated at its one end to the lower portion of the upper coupling
pipe. The other end of the lower coupling shaft having a predetermined curvature forming a rack thereon and has a through hole formed in the cross direction of the lower coupling shaft. The lower jack includes a chute in which pinions are formed to be meshed with the rack, and coupling holes located at both sides of the chute member are formed. A lower holder which is closely coupled to the outer surface of the chute.