Selected measurement results of plasma spheroidization of tungsten and rhenium powders are presented in the paper. The powders can be applied for production of sinters intended for armor-piercing penetrating cores (kinetic energy penetrators) or high-current electric contacts. Spheroidization of these powders was carried out on the stand for plasma spraying in a chamber filled with neutral gas. Changes of shape and size of powder particles after spheroidization are demonstrated. Measurement results of internal stresses in powder particles are presented.