<p>The method of nitriding involves the use of glow discharge for surface modification. It is commonly used to improve the endurance, resistance to wear, resistance to corrosion, and surface hardness of steel. The study's objective was to evaluate the nitriding process (liquid, gas, and plasma nitriding) on various grades of steel (20MnCr₅, EN19, and EN41B) in terms of hardness attributes, case depth analysis, dimensional correctness, and white layer production. The microstructural analysis was conducted using a metallurgical microscope, a microhardness tester, and XRD-EDS. The white layer is the uppermost layer characterized by a significant concentration of nitrogen atoms, situated between the surface and the underlying layer. The findings indicate that for EN19, the decrease in the white layer was less than 10 microns, making it almost 60% smaller than the other two gear materials, specifically 20MnCr₅ and EN41B. 20MnCr₅ exhibits lower hardness and diminished core strength compared to the other two materials, EN19 and EN41B. The formation of precipitates is smaller in size, and there are a greater number in both alloy steels. As the temperature increases, the size, distortion, and visibility of the precipitates increase.</p>