The great majority of the vast number of valves upplied every year to industry are made from nonferrous materials, chiefly bronze or brass. Bronze in valve manufacture is usuall an alloy of copper, tin, lead, and zinc of the required 85/5/5/5 this or must 87/7/3/3 specified type. If a zinc free bronze is required this must be specified. The a physical strength, structural stability and corrosion resistance of bronze in particular makes it very suitable for a wide variety of applications in the mainstream of industrial requirements. Bronze also lends itself particularly well to economic large scale production of the smaller size valves and, conveniently, the bulk of industrial applications is for valve sizes up to 100MM. Although bonze valves are used mostly for applications at relatively modest temperatures, some grades of bronze are suitable for temperatures up to around 280°C. At the other end of the temperature scale the attribute of not becoming embrittled at very low temperatures, possessed by most copper alloys, has led to bronzes being widely used for cryogenic services such as liquid oxygen and nitrogen where temperatures below 180°C prevail.