A bronze with a high degree of hardness, elasticity, and toughness, that contains a small amount of phosphorus. This group of copper, tin and phosphorus alloys contains from 1.3 to 10%tin and 0.03 to 0.35% phosphorus. These alloys may be brazed, soft soldered, and flash welded. They may also be welded with resistance spot welding and gas metal arc welding processes. Oxyfuel gas welding and shielded metal arc welding of the phosphor-bronze alloys produce only fair results.
A free-machining variety of phosphor bronze contains 3.5 to 4.5% lead, 3.5 to 4.5% tin, 1.5 to 4.5% zinc and 0.01 to 0.50% phosphorus. The free-machining alloys can be soldered, brazed, or flash welded, but other welding processes are not recommended.
Coated or uncoated welding rods are available for several of these alloys. Melting range for these alloys is 1035 to 1075°C (1900 to 1970°F) for the lower tin alloys, and 845 to 1000°C (1550 to 1830°F) for the higher tin alloys.