Nitriding is a case hardening process that depends on the absorption of nitrogen into the steel. All machining, stress relieving, as well as hardening and tempering are normally carried out before nitriding and oxidation process after nitiriding. The parts are heated in a special container through which ammonia gas is allowed to pass. Materials 42CrMo4, 38CrMoAl, 41CrAlMo7-10 are the most common nitriding steel, the surface hardness reaches HV950-1100, Min. effective depth is 0.3mm. The advantage of nitriding is mainly the reduced distortion behavior and still gives a high surface strength and ductile core. Nitriding can also increase the corrosion resistance of a component. Typical application is cylinder tubes and rods for metal recycling equipments.