A copper-base alloy containing up to 10% tin, which has been deoxidized with phosphorus in varying amounts of less than 1%. Temper is imparted by cold rolling, resulting in greater tensile strength and hardness than in most copper-base alloys or either of its alloying elements copper or tin. The various tempers from One Number Hard to Ten Numbers Hard are classified in hardness by the number of B&S Gages reduction in dimension from the previous soft or as-annealed state. Phosphor Bronze is not heat treatable for purposes of hardness development. It does not withstand elevated temperatures very well and should not be used in service above 225 (degrees) F. even after stress relieving treatment at 325 (degrees) to 350 (degrees) F. It has excellent electrical properties, corrosion resistant comparable to copper; great toughness and resistance to fatigue. Rated good for soft soldering, silver alloy brazing, oxyacetylene, carbon arc and resistance welding.