Bronze is the term used for alloys of copper and tin. Sometimes, bronze is also found with other elements such as phosphorus, manganese, aluminum, or silicon. It is strong and tough, and has wide range of uses in industry. Bronze pumps are commonly specified for use on seawater, hot water and certain chemicals. Sintered bronze is a porous material, which can be impregnated with oil, graphite or PTFE. It is not suitable for heavily loaded applications but is of great use where lubrication is inconvenient.