What material are piston rings commonly made from?

Piston rings are commonly made from self-lubricating materials due to the critical function they perform in an engine. The primary roles of piston rings include sealing the combustion chamber, controlling oil consumption, and regulating heat transfer from the piston to the cylinder wall. Self-lubricating materials often contain compositions that allow for reduced friction between the piston and the cylinder wall, enhancing the overall efficiency of the engine and prolonging the lifespan of the piston rings by minimizing wear.

Materials that offer self-lubrication can help prevent the piston rings from seizing and ensure smoother operation under high pressures and temperatures, which are characteristic of engine operation. This characteristic is particularly beneficial for maintaining performance over time, making it a preferred choice in modern engine design.

In contrast, while other materials might have their advantages in specific applications, they do not meet the requirements of functionality that self-lubricating materials provide in the context of piston rings.