Stainless steel (SS 302) and high carbon steel (HCS) substrates were nitrided in a pot type arc plasma furnace in the temperature range 1100-120 degrees C under different gas (Ar, N-2, H-2) mixture configurations for twenty minutes each. The nitrided surfaces were characterized by XRD, SEM, metallography and microhardness. Depth of the nitride layer grown was found between 40 to 50 mu m. Microhardness for SS 302 was observed to increase by about three to four times but for HCS the increase was not more than two times. The major compound phases to grow by this method were indentified to be Fe2-3N(epsilon), (Cr, Fe)N1-x and CrN in case of SS 302 whereas for HCS the phases were recognised as Fe2-3N(epsilon), (Cr,Fe)N1-x, Fe2N(xi) and WN. Further details about the experiment and characterization of arc plasma nitrided steel are reported and discussed in this paper.