## Namura NA-40025R Piston Rings 102.97mm - Reliability and Performance Namura NA-40025R piston rings with a diameter of 102.97mm are a key element for ensuring optimal performance, efficiency, and engine durability. Although often overlooked, they play a fundamental role in the proper functioning of the piston. Namura, a renowned manufacturer of motorcycle and scooter parts, precisely designs its rings, taking into account the specifics of their application. The type of cylinder sleeve, its coating, engine size, and piston stroke (2 or 4 stroke) - all these factors influence the selection of the optimal material composition of the rings, guaranteeing their reliability under given operating conditions. ### Compression Rings Made of highly ductile cast iron or stainless steel alloy, they are characterized by excellent wear resistance and provide a tight seal. Additionally, to meet the requirements of specific applications, compression rings can be coated with chrome, phosphate, or nitride. ### Oil Rings Namura oil rings consist of three separate components: two scraper rails made of highly ductile cast iron or stainless steel alloy, coated with chrome, nitride, or phosphate, and one expander ring made of stainless steel. This solution ensures optimal lubrication and prevents excessive engine wear. By choosing Namura NA-40025R piston rings, you invest in the quality and long life of your engine.