In the early days of manufacture the term bronze was applied to a non-corrosive metal made of a mixture of copper and tin, dark in color, hard in temper, and of high tensile strength. Today bronze refers to any metal that possesses any of the above characteristics. In order to distinguish the different bronzes, a prefix should be used, such as "Tobin," "phosphor," "naval," "manganese," etc.

Tobin-bronze is a composition of copper, tin, and zinc, in such proportions as are necessary to secure the physical properties and the resistance to corrosion desirable in a metal intended for engineering purposes. It has a bright golden color and resists the corrosive action of sea water.

Phosphor-bronze, which is bronze containing phosphorus, resists shocks. Hence it is used for the bearings of rolling mills, railway axles, for valves of air pumps, etc. It is affected by the heat more than is gun-metal. Phosphor-bronze offers great resistance to corrosion, has great tensile strength, and has no tendency to disintegration. It may be made into springs without "setting" or crystallizing. It is better than any other copper alloy because of its antifriction properties.

Naval-bronze is made according to specifications of the United States Navy. It is particularly adapted to marine engineering, where strength must be accompanied by non-corrodibility.

Manganese-bronze is an alloy of copper, zinc, and tin, deoxidized by means of manganese. It may be readily rolled or forged at a red heat resulting in the production of an exceedingly tough, dense, and close-grained metal. It will resist vibratory and sudden stresses and shocks, and will not rust or corrode in the presence of air or sea water.