A piston ring must have both spring, Like tension and the properties so as to develop into true circle when closed. In the combustion chamber of engine, Npr s piston rings serve to seal, Dissipate heat and prevent, Combustion gas control lubricating, Wear and oil seizure under the severe conditions of operation. Now that engines are mandated to be more compact, Lighter, And more sophisticated the selection, In performance favored by piston ring materials has been widened to include steel in combination with the traditional cast created specifically, Iron. Moreover for the use of of enhance their wear resistance and durability, They also undergo various surface treatments including nitriding and pvd treatment.