Often overlooked and unglamorous, they are an essential part of piston performance, engine efficiency, and durability. The materials used in the manufacturing of piston rings are one of the most critical factors in their performance. Namuras rings are designed specifically for their application. The type of cylinder sleeve, sleeve coating, size of the engine, and the stroke (2 or 4) all play a role in determining the composition best suited for the operating environment. While it may vary by model, we have outlined some of the key features below:Compression RingsComposed of either a highly ductile cast iron or stainless steel alloy; both materials possess excellent wear resistance and provide a gastight seal. Chrome, phosphate and nitride coatings are also used to meet the demands of the application.Oil RingsOil rings consist of three separate components. Two scraper rails constructed from highly ductile cast iron or a stainless steel alloy and also have a chrome, nitride, or phosphate coating. The single expansion ring is manufactured from stainless steel.Rings included vary based on your vehicle.