The paper deals with the influence of the nozzle internal geometry on arc characteristics and metal cutting process parameters. The latters have been established to
depend on the angle of inclination of the nozzle channel. Optimizing this parameter allowed the electric current density as well as the plasma flow velocity at the nozzle outlet to be increased that results ultimately in plasma cutting efficiency to rise. So, the plasmatron designed is capable of cutting copper of 120 mm and stainless steel of 200 mm in thickness at cutting rate of 8 m/h and current 900 A.