BRONZE

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.

The term bronze is generally applied to anycopper alloy that has as the principal alloyingelement a metal other than zinc or nickel. Originallythe term was used to identify copper–tinalloys that had tin as the only, or principal,alloying element. Some brasses are calledbronzes because of their color, or because theycontain some tin. Most commercial copper–tinbronzes are now modified with zinc, lead, silver,or other elements.
Bronze is used in bearings, bushings, gears,valves, and other fitt