C51900 Phosphor Bronze
C51900 Phosphor Bronze
C51900 Phosphor Bronze (6% Tin, Leaded) is a high-strength copper-tin-lead-phosphorus alloy, offering excellent machinability, wear resistance, and corrosion resistance. It is widely used in bearings, bushings, gears, valve components, and electrical connectors.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Copper (Cu + Named Elements) | 99.5 | Rem |
| Tin (Sn) | 5.5 | 6.5 |
| Phosphorus (P) | 0.03 | 0.35 |
| Lead (Pb) | 0.3 | 0.6 |
| Zinc (Zn) | – | 1.0 |
| Iron (Fe) | – | 0.15 |
Mechanical Properties (Typical at 20°C)
| Form | Temper | Code | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation (%) | Hardness |
|---|---|---|---|---|---|---|
| Rod / Wire | Half Hard | H02 | 55 | 38 | 28 | 65 HB |
| Rod / Wire | Hard | H04 | 70 | 55 | 20 | 80 HB |
| Flat Products | Spring | H08 | 95 | 80 | 4 | 90 HB |
Physical Properties
| Property | Value |
|---|---|
| Melting Point | 1800–1830°F |
| Density | 0.33 lb/cu in |
| Specific Gravity | 8.9 |
| Electrical Conductivity | 15–18% IACS |
| Thermal Conductivity | 50–55 Btu/sq ft/ft/hr/°F |
| Thermal Expansion | 9.5 × 10⁻⁶ /°F |
| Modulus of Elasticity | 15,000 ksi |
| Modulus of Rigidity | 5,500 ksi |
Fabrication & Machining
| Process | Suitability |
|---|---|
| Soldering | Excellent |
| Brazing | Good |
| Cold Working | Very Good |
| Machinability | 80–85% Rating |
| Welding | Not Recommended |
Thermal Treatment
| Process | Min Temp (°F) | Max Temp (°F) |
|---|---|---|
| Annealing | 850 | 1200 |
Applications
Bearings & Bushings
Electrical Connectors & Contacts
Gears & Pinions
Valve Components
Industrial Machinery
Benefits: High-strength, excellent wear and corrosion resistance, superior 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
