Application of new principles of gas-vortex stabilization allows to increase efficiency and quality of air-plasma cutting of metals. The use of symmetrical supply of plasma-forming gas to the gas-vortex system, the use of two expansion chambers and swirlers with a step distribution of gas through the channels of the gas-air path and tangential gas supply to the nozzle makes it possible to increase the uniformity of the gas flow distribution over the section of the plasma torch nozzle, improve the kinematic and energy parameters of the plasma arc (jet) for single-flow plasmatrons of the PMVR-5 series. Additional compression of the plasma flow due to the secondary gas flow in the PMVR-9 series plasma torches ("narrow-jet plasma" technology) makes it possible to further increase the uniformity and kinematic characteristics of the plasma flow at a small distance from the plasma torch nozzle. The developed plasma torches can significantly improve the performance and energy efficiency of cutting technology, as well as improve the quality of cutting seams. When cutting with new plasmatrons of structural steels of medium thickness, sub-sequent welding can be performed without additional machining of the cutting seams.