Rezumat
The paper presents the possibility to reduce the average drawing force in the technologies for obtain- ing tubes, rods and wires, when the tool is located in the oscillation maximum of the ultrasonic waves and actuated parallel to the drawing direction. This reduction is explained by the frictional force vector reversal during the time T/2-2t1 within a complete oscillation period, when vtr/vv<1. This fact justifies the use of ultra- sonic energy in the plastic deformation processes of resistive to cold drawing metals.