Abstract: A support jack, in particular for supporting semitrailers, includes a vertically telescopically displaceable supporting element having an outer sleeve and an inner sleeve, each sleeve having a rectangular cross-section with four sidewalls in each case. At least one sidewall at least of the inner sleeve has an additional wall plate. Another alternative proposes that at least one sidewall at least of the inner sleeve consists of a wall plate which the two adjacent sidewalls are fixed. An arrangement of such a support jack on the lower side of a vehicle is also described.

Abstract: A support jack for supporting semitrailers including a vertically telescopically displaceable supporting device having an outer sleeve and an inner sleeve. A spindle nut has first means and second means for being positively detachably connected to the sleeves. The first means interact with means of the inner sleeve for fixing the spindle nut in the direction of the longitudinal axis of the support jack. The second means interact with means of the outer sleeve for fixing the spindle nut in the direction of rotation about the longitudinal axis. A method of assembling a support jack is also described, in which the spindle nut is connected detachably to the inner sleeve by means of at least one translatory and one rotary joining movement or at least by means of two translatory joining movements.