C51000 Phosphor Bronze

C51000 Phosphor Bronze

C51000 Phosphor Bronze is a high-quality copper-tin-phosphorus alloy known for its excellent corrosion resistance, moderate strength, and outstanding electrical conductivity. This alloy is ideal for electrical connectors, springs, bearings, and marine components.


Chemical Composition

ElementMin (%)Max (%)
Copper (Cu + Named Elements)99.5Rem
Tin (Sn)4.06.0
Phosphorus (P)0.030.35
Lead (Pb)0.35
Zinc (Zn)1.0
Iron (Fe)0.15

Mechanical Properties (Typical at 20°C)

FormTemperCodeTensile Strength (ksi)Yield Strength (ksi)Elongation (%)Hardness
Rod / WireHalf HardH0250353060 HB
Rod / WireHardH0465502075 HB
Flat ProductsSpringH089070585 HB

Physical Properties

PropertyValue
Melting Point1750–1800°F
Density0.32 lb/cu in
Specific Gravity8.9
Electrical Conductivity18–20% IACS
Thermal Conductivity50 Btu/sq ft/ft/hr/°F
Thermal Expansion9.6 × 10⁻⁶ /°F
Modulus of Elasticity15,000 ksi
Modulus of Rigidity5,500 ksi

Fabrication & Machining

ProcessSuitability
SolderingExcellent
BrazingGood
Cold WorkingGood
Machinability75–80% Rating
WeldingNot Recommended

Thermal Treatment

ProcessMin Temp (°F)Max Temp (°F)
Annealing8501200

Applications

  • Electrical Connectors & Contacts

  • Springs & Precision Components

  • Bearings & Bushings

  • Marine Components

  • Industrial Machinery

Benefits: Corrosion-resistant, excellent electrical conductivity, moderate strength, good machinability.


Standards

  • ASTM B103/B103M – Plate, Sheet, Strip

  • ASTM B139/B139M – Rod, Bar, Shapes

  • SAE J461/J463 – Wrought Copper Alloys

  • AMS 4520 – Cold Rolled Bronze Strip

  • MIL-B-13501 – Bearings & Bushings