What are the materials used in inlet and exhaust valve?

Inlet and exhaust valves are typically made from high-strength materials to withstand extreme temperatures and pressures. Common materials include stainless steel, which offers good corrosion resistance, and various alloys such as titanium for lightweight applications. Some valves may also be coated with hard materials like chrome or nitriding to enhance durability and reduce wear. Additionally, specific grades of steel, such as 21-4N or 31-8N, are often used for their heat resistance and strength.