Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. It is used for decoration for its bright gold-like appearance; for applications where low friction is required such as locks, gears, bearings, doorknobs, ammunition, and valves; for plumbing and electrical applications; and extensively in musical instruments such as horns and bells for its acoustic properties. Because it is softer than most other metals, in general use, brass is often used in situations where it is important that sparks not be struck, as in fittings and tools around explosive gases.

Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal. However, since "bronze" is a somewhat imprecise term, and historical pieces have variable compositions, in particular with an unclear boundary with brass, modern museum and scholarly descriptions of older objects increasingly use the more cautious and inclusive term "copper alloy" instead. Historically the term latten was used for such alloys.

Gunmetal
Gunmetal, also known as red brass in the United States, is a type of bronze, an alloy of copper, tin, and zinc. Originally used chiefly for making guns, gunmetal was eventually superseded by steel. Gunmetal casts and machines well and is resistant to corrosion from steam and salt water, and is used to make steam and hydraulic castings, valves, and gears, and also statues and various small objects, e.g. buttons.

Bellmetal
Bell metal is a hard alloy used for making bells. It is a form of bronze, usually approximately 4:1 ratio of copper to tin (78% copper, 22% tin).