Abstract: The embodiment of the invention disclosed herein is directed to a lifting jack having an upstanding hollow strut member for rotatably receiving a screw rod therein. The strut member has a flat front wall which forms a glide surface and inwardly turned portions to form a rear glide surface. The inwardly turned portions are spaced apart to provide a longitudinal opening through which extends a slide member secured to a load-lifting support element. The upper end of the screw rod is provided with a non-circular configuration having flat side wall portions and shoulder portions extending therefrom to be inserted into a recess formed in a washer which is to rotate therewith. The washer bears against a pair of thrust disks which are positioned between the upper end of the strut member and the washer. The thrust disks provide multiple thrust bearing surfaces for increased wearability and ease of turning under heavy loads.