Overview
C519 Phosphor Bronze, also known as C51900 Phosphor Bronze or 6% Tin Bronze, is a high-strength copper-tin-phosphorus alloy widely recognized for its outstanding combination of spring properties, fatigue resistance, wear resistance, corrosion resistance, and mechanical strength.
Containing approximately 6% tin and a controlled phosphorus addition, C519 offers higher strength and better spring performance than C510 phosphor bronze while maintaining good formability and corrosion resistance. It is extensively used in electrical, electronics, automotive, aerospace, marine, and industrial applications.
C519 phosphor bronze is widely used in:
- Electrical Connectors
- Spring Contacts
- Switch Components
- Relay Parts
- Precision Springs
- Bearings
- Bushings
- Marine Hardware
Because of its excellent elastic properties and durability, C519 is one of the most widely used phosphor bronze alloys for precision spring applications.
Material Specification
| Property | Value |
|---|---|
| Material Designation | C519 Phosphor Bronze |
| UNS Number | C51900 |
| Common Name | 6% Phosphor Bronze |
| Standard | ASTM B103 / ASTM B139 |
| Material Family | Copper-Tin-Phosphorus Alloy |
| Density | 8.84 g/cm³ |
| Magnetic Property | Non-Magnetic |
| Typical Supply Condition | Annealed, Half-Hard, Full Hard, Spring Temper |
| Standard Forms | Sheet, Strip, Plate, Rod, Wire |
Chemical Composition
| Element | Content (%) |
|---|---|
| Copper (Cu) | Balance |
| Tin (Sn) | 5.50–7.00 |
| Phosphorus (P) | 0.03–0.35 |
| Zinc (Zn) | ≤0.30 |
| Iron (Fe) | ≤0.10 |
| Lead (Pb) | ≤0.05 |
The increased tin content improves strength, wear resistance, and fatigue performance compared with C510.
Mechanical Properties
Annealed Condition
| Property | Value |
|---|---|
| Tensile Strength | 380–550 MPa |
| Yield Strength | 180–320 MPa |
| Elongation | 15–35% |
| Hardness | 80–130 HB |
| Elastic Modulus | 115 GPa |
Spring Temper Condition
| Property | Value |
|---|---|
| Tensile Strength | 700–900 MPa |
| Yield Strength | 550–800 MPa |
| Hardness | 200–280 HB |
Physical Properties
| Property | Value |
|---|---|
| Density | 8.84 g/cm³ |
| Melting Point | 950–1030°C |
| Thermal Conductivity | 63 W/m·K |
| Electrical Conductivity | 13–14% IACS |
| Electrical Resistivity | 0.125 μΩ·m |
| Thermal Expansion Coefficient | 17.8 × 10⁻⁶/K |
| Specific Heat Capacity | 377 J/kg·K |
Electrical Conductivity
| Material | Conductivity (% IACS) |
|---|---|
| C110 Copper | 100 |
| C260 Brass | 28 |
| C510 Bronze | 15 |
| C519 Bronze | 13–14 |
| C521 Bronze | 13 |
Although lower than copper and brass, C519 provides sufficient conductivity for precision electrical contacts and spring applications.
Thermal Conductivity
| Material | Thermal Conductivity (W/m·K) |
|---|---|
| C110 Copper | 390 |
| C260 Brass | 120 |
| C510 Bronze | 67 |
| C519 Bronze | 63 |
| C521 Bronze | 63 |
| Stainless Steel 304 | 16 |
Corrosion Resistance
| Environment | Performance |
|---|---|
| Indoor Environment | Excellent |
| Fresh Water | Excellent |
| Marine Atmosphere | Excellent |
| Salt Water | Excellent |
| Industrial Environment | Excellent |
| Chemical Exposure | Good |
C519 offers outstanding corrosion resistance in marine, industrial, and atmospheric environments.
Recommended surface treatments:
- Tin Plating
- Nickel Plating
- Silver Plating
- Gold Plating
- Electropolishing
- Passivation
Wear Resistance
| Property | Performance |
|---|---|
| Sliding Wear Resistance | Excellent |
| Galling Resistance | Excellent |
| Bearing Performance | Excellent |
| Fatigue Resistance | Outstanding |
C519 is frequently selected for demanding wear and spring applications.
Weldability
| Welding Process | Rating |
|---|---|
| TIG Welding | Good |
| MIG Welding | Good |
| Resistance Welding | Excellent |
| Brazing | Excellent |
| Soldering | Excellent |
Machinability
| Process | Rating |
|---|---|
| CNC Turning | Good |
| CNC Milling | Good |
| Drilling | Good |
| Grinding | Good |
| Stamping | Excellent |
| Forming | Excellent |
Machinability Comparison
| Material | Machinability |
|---|---|
| C360 Brass | Excellent |
| C519 Bronze | Good |
| C510 Bronze | Good |
| C521 Bronze | Good |
| Stainless Steel 304 | Moderate |
Heat Treatment
Stress Relief Annealing
| Parameter | Value |
|---|---|
| Temperature | 250–350°C |
| Cooling Method | Air Cool |
Annealing
| Parameter | Value |
|---|---|
| Temperature | 500–700°C |
| Cooling Method | Air Cool |
Heat Treatability
| Property | Performance |
|---|---|
| Hardening by Heat Treatment | No |
| Cold Work Strengthening | Yes |
| Spring Temper Available | Yes |
C519 achieves its high strength primarily through cold work and temper processing.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| UNS (USA) | C51900 |
| ASTM | C519 |
| EN (Europe) | CuSn6 |
| DIN (Germany) | CW452K |
| JIS (Japan) | C5191 |
| ISO | CuSn6 |
| GB/T (China) | QSn6.5-0.1 |
Available Forms
| Product Type | Availability |
|---|---|
| Sheet | Yes |
| Strip | Yes |
| Plate | Yes |
| Round Bar | Yes |
| Flat Bar | Yes |
| Wire | Yes |
| Spring Strip | Yes |
Typical Applications
Electrical Industry
- Electrical Connectors
- Spring Contacts
- Switch Components
- Relay Parts
Electronics Industry
- Precision Contact Springs
- Connector Terminals
- Battery Contacts
- Shielding Components
Automotive Industry
- Spring Clips
- Electrical Connectors
- Contact Components
- Sensor Hardware
Marine Industry
- Marine Fasteners
- Corrosion Resistant Components
- Offshore Equipment Parts
Mechanical Industry
- Bearings
- Bushings
- Wear Plates
- Thrust Washers
Aerospace Industry
- Precision Springs
- Electrical Hardware
- High-Reliability Components
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| CNC Machining | Good |
| Stamping | Outstanding |
| Forming | Outstanding |
| Welding | Good |
| Brazing | Excellent |
| Soldering | Excellent |
| Electroplating | Excellent |
Advantages
Outstanding Spring Properties
Excellent elasticity and recovery characteristics.
High Strength
Higher strength than C510 phosphor bronze.
Excellent Fatigue Resistance
Ideal for repeated-load spring applications.
Excellent Corrosion Resistance
Suitable for marine and industrial environments.
Good Wear Resistance
Widely used for bearings and sliding components.
Long Service Life
Maintains performance in demanding operating conditions.
Limitations
Lower Conductivity Than Copper
Not suitable for high-current power transmission.
Higher Cost Than Brass
Premium alloy with higher material cost.
Lower Thermal Conductivity
Compared with pure copper alloys.
More Difficult Forming Than Brass
Requires higher forming forces.
Comparison with Other Bronze Grades
| Property | C519 | C510 | C521 | C544 |
|---|---|---|---|---|
| Tin Content | 6% | 5% | 8% | 4% |
| Strength | Higher | High | Highest | Moderate |
| Conductivity | 13–14% | 15% | 13% | 15% |
| Spring Properties | Outstanding | Excellent | Outstanding | Good |
| Corrosion Resistance | Excellent | Excellent | Excellent | Good |
Comparison with Common Copper Alloys
| Material | Conductivity | Strength | Spring Properties |
|---|---|---|---|
| C519 Bronze | 13–14% IACS | High | Outstanding |
| C510 Bronze | 15% IACS | High | Excellent |
| C521 Bronze | 13% IACS | Higher | Outstanding |
| C260 Brass | 28% IACS | Moderate | Good |
| C110 Copper | 100% IACS | Low | Poor |
Available Surface Finishes
Raw Finishes
- Mill Finish
- Annealed Finish
- Spring Temper Finish
Functional Finishes
- Precision Stamped Finish
- Polished Finish
- Brushed Finish
Conductive Finishes
- Tin Plated
- Silver Plated
- Gold Plated
- Nickel Plated
Frequently Asked Questions (FAQ)
What is C519 phosphor bronze?
C519 is a copper-tin-phosphorus alloy containing approximately 6% tin and is widely used for spring and electrical applications.
What is C519 used for?
Typical applications include:
- Electrical Connectors
- Spring Contacts
- Switch Components
- Bearings
- Marine Hardware
What is the equivalent material to C519?
Common equivalents include:
- CuSn6
- CW452K
- C5191
- QSn6.5-0.1
What is the difference between C519 and C510?
| Property | C519 | C510 |
|---|---|---|
| Tin Content | Higher | Lower |
| Strength | Higher | High |
| Conductivity | Slightly Lower | Higher |
| Spring Properties | Better | Excellent |
Is C519 suitable for springs?
Yes. C519 is one of the most widely used phosphor bronze spring materials.
Is C519 corrosion resistant?
Yes. It provides excellent resistance to marine and industrial environments.
Can C519 be machined?
Yes. C519 offers good machinability and excellent stamping performance.
Why choose C519 phosphor bronze?
Because it combines:
- Outstanding Spring Performance
- High Strength
- Excellent Fatigue Resistance
- Excellent Corrosion Resistance
- Good Wear Resistance
Is C519 suitable for electrical contacts?
Yes. C519 is widely used for connector terminals and spring contacts.
Does GCNOV provide custom manufacturing services for C519 bronze?
Yes. GCNOV provides:
- CNC Machining
- Precision Stamping
- Spring Component Manufacturing
- Electrical Connector Production
- Surface Plating
- Prototype Development
- Low-Volume Production
- Mass Production