PURPOSE:A spinning ring in which a layer of Fe-N compound and another layer of Fe-C-N martensite are formed on the surface on which the traveller slides, thus being capable of containing oil due to very fine pores near the surface and showing high lubricating performance because of its wearing and corrosion resistance. CONSTITUTION:The ring material of case-hardened steel (S 15 CK) containing 0.15wt% carbon is subjected to soft nitriding treatment A in a soft gas-nitriding furnace. Then, the temperature is gradually raised and on the way of heating (C- step) the gas fot the treatment A is evacuated and simultaneously another gas for carburizing is introduced. After the carburizing treatment is effected, the material is quenched by rapid cooling. The layers formed by the treatments A and C are little defective to give the stable and double layers of nitrided and carburized irons.