... life ball screw jack description:1.Model: RNK-0.5T,1T,2T,3T,5T,10T,15T,20T2.Configuration: worm and worm gear,bearing ... ,housing and ball screw3.Ball screw jack assemblies use small balls to roll between the ... and precise positioning.5.Ball screw jack stand loading capacity is 1/3 Lead screw jack loading capacity.6.Ball screw jack is more precision ...