Internal retaining rings are circular fasteners used to secure components within a housing or bore. They fit into a groove on the inside diameter of a shaft or housing, preventing parts from moving out of place. These rings are commonly made from materials like stainless steel or carbon steel, providing durability and resistance to wear. These rings come in various sizes and styles, including snap rings and spiral rings, to accommodate different applications. They are widely used in machinery, automotive, and aerospace industries, ensuring that components remain securely in position during operation.