In the single nut assembly, between the ball and the ball track exits a minimum axial clearance. In many cases it is necessary to eliminate this clearance to increase the positioning accuracy and assembly rigidity. This is obtained by preloading two nuts to produce an elastic deformation on the rolling elements. Preload value will be indicated by the customer, depending upon his working conditions, the value recommended is 1/3 of the mean workload Fm. If this value is not indicated, ground ballscrews with double nut assembly will be supplied with an axial preload equivalent to the 7 % of the dynamic load capacity Cam.

IPIRANGA preload system is by tension to the screw on which the nuts are separated by a spacer ring. Temperature rises can produce a reduction in preload because of screw expanding.