Brass & Copper
Brass is an alloy of copper and zinc. It is bright yellow and one of the more important alloys of copper. The proportion of copper varies according to the use of the metal. Commercial brass contains about 90 percent copper and 10 percent zinc. The working characteristics are almost identical to those of copper.
Copper, is a base metal that is the oldest metal known. It is easily identified by its rich reddish-brown color. The metal is a good conductor of electricity, second only to silver. Much copper is used for art metalwork because of its easy-to-work qualities. It can be shaped easily but becomes hard when worked and must be softened or annealed. This is done by heating the metal to a cherry-red color and quenching or cooling it in water. Copper can be readily joined with rivets, and both soft and hard solders.
When copper is exposed to the atmosphere for a period of time a greenish tinge called PATINA develops on its surface(s). This can be removed by polishing. However, on certain copper articles, a fine natural patina is desirable.
Copper can be purchased in a large variety of shapes and sizes. Copper sheet is measured by one of two methods: