COPPER BERYLLIUM

Beryllium copper is not really a compound, but a very useful alloy that often contains other metals such as cobalt or nickel in small amounts. It is a hard, strong alloy with excellent electrical conductivity, which makes it very useful in electrical switching equipment owing to its nonsparking qualities. It makes excellent spot-welding electrodes, springs, and metal bushings, cams, and diaphragms.

Any of a group of copper-tin alloys usually containing 0.5–10% of tin. They are generally harder, stronger in compression, and more corrosion resistant than brass. Zinc is often added, as in gunmetal (2–4% zinc), to increase strength and corrosion-resistance; bronze coins often contain more zinc (2.5%) than tin (0.5%). The presence of lead improves its machining qualities.
Some copper-rich alloys containing no tin are also called bronzes. Aluminum bronzes, for example, with up to 10% aluminum, are strong, resistant to corrosion and wear, and can be worked cold or hot; silicon bronzes, with 1–5% silicon, have high corrosion-resistance; beryllium bronzes, with about 2% beryllium, are very hard and strong.