Tin alloy is a type of metal composed of tin and other elements. PEWTER, a tin alloy composed of tin, copper, and antimony, is commonly used in jewelry and tableware. BRONZE, another tin alloy composed of tin and copper, is often used for sculptures and tools. Terne, a tin alloy composed of tin and lead, is used for roofing and plumbing. Gunmetal, a tin alloy composed of tin, copper, and zinc, is used for firearms and locks. Oroide, a tin alloy composed of tin, copper, and nickel, is used for decorative items.