A machine reamer is a cutting tool used in machining to enlarge and finish holes with precision. It is designed to create a smooth, accurate surface inside a hole, ensuring that it meets specific size and tolerance requirements. Typically made from high-speed steel or carbide, machine reamers can be used in various materials, including metals and plastics. These tools come in different types, such as straight reamers and tapered reamers, each suited for specific applications. Machine reamers are commonly used in industries like automotive and aerospace, where precision is crucial for the performance and safety of components.