The object of research is the parts and assemblies of modern construction machines and mechanisms is important for reducing operating costs, increasing productivity, reducing downtime for repairs, improving their quality and competitiveness, which naturally imposes strict requirements on their mechanical properties, reliability, strength, and durability. The use of simple manufacturing technologies is also of great importance. One of the effective ways to increase the mechanical properties of thin-walled parts of surface-plastic deformation (PPD), among which a special place is occupied by methods of PPD using ultrasonic vibrations (UV). The purpose of the work is to improve the physical and mechanical characteristics of their thin-walled parts using the technology of bilateral ultrasonic smoothing of their working surfaces. Method. A new method of ultrasonic bilateral hardening of thin-walled sheet materials has been developed, which makes it possible to obtain blanks in the form of sheet materials hardened on both sides, from which thin-walled machine parts are obtained by pressure treatment methods. Results. Experimental studies have established simplified quadratic mathematical models of the dependences of the microhardness of the hardened layers and the depth of their penetration on the technological parameters of the ultrasonic smoothing process. It is shown that bilateral ultrasonic processing of thin-walled plates increases their axial stiffness by up to 49.6% with a simultaneous increase in their plasticity, which makes it possible to significantly improve the conditions for stamping complex machine parts from such plates. It is established that using the technology of bilateral ultrasonic hardening of sheet blanks for the manufacture of them by methods of processing materials by pressure allows up to 20...30% to improve the weight characteristics of manufactured thin-walled machine parts.