C51000 Phosphor Bronze
UNS C51000 Tin-Phosphor Bronze
C51000 is a high-performance tin-phosphor bronze containing approximately 5% tin and small additions of phosphorus. The phosphorus addition acts as a deoxidizer and increases hardness, strength, and fatigue performance, making C51000 one of the most widely used spring and electrical contact alloys in the world.
C51000 develops excellent strength and fatigue resistance through cold work, and is supplied in a wide range of tempers tailored to specific stamping, forming, and spring applications. It offers good corrosion resistance, useful electrical conductivity for a high-strength alloy, and reliable, repeatable performance over millions of cycles.
It is particularly well-suited to electrical connectors, switch components, and precision stampings where consistent spring properties and resistance to fatigue are critical.
Common Names & Cross-References
Designation | Value |
|---|---|
Common Names | Phosphor Bronze 5% A, PB1, Tin Bronze, Phosphor Bronze |
UNS | C51000 |
CDA | 510 |
British Standard | PB102 |
EN (Europe) | CuSn5 |
JIS (Japan) | C5101 |
C51000 Chemical Composition
Element | Composition (%) |
|---|---|
Copper (Cu) | Balance |
Tin (Sn) | 4.2 – 5.8 |
Phosphorus (P) | 0.03 – 0.35 |
Lead (Pb) | 0.05 max |
Zinc (Zn) | 0.30 max |
Iron (Fe) | 0.10 max |
Typical Mechanical Properties
Property | Annealed (O60) | Spring Temper (H08) |
|---|---|---|
Tensile Strength | 47 ksi (324 MPa) | 100-115 ksi (690-790 MPa) |
Yield Strength (0.2%) | 19 ksi (131 MPa) | 85-100 ksi (586-690 MPa) |
Elongation (in 2 in.) | 64% | 3-6% |
Hardness | Rockwell B 28 | Rockwell B 96-99 |
Key Features & Advantages
- Excellent fatigue strength and spring performance
- High strength developed through cold work
- Good corrosion resistance, especially in marine and industrial atmospheres
- Strong wear resistance for bearing and bushing service
- Good solderability and consistent electrical performance
- Available in tightly controlled tempers for precision stamping
Common Applications of C51000
- Springs, clips, and contact arms
- Electrical terminals, connectors, and switch components
- Precision stampings and formed parts
- Bushings, bearings, and wear components
- Diaphragms and Bourdon tubes
- Fasteners requiring fatigue resistance
Primary Markets Served
- Electrical & Electronic
- Industrial Manufacturing
- Automotive
- Hardware & Tools
When to Specify C51000
- C51000 vs. C52100 (Phosphor Bronze 8%) — C52100 has higher tin content for greater strength and corrosion resistance, but at higher cost. C51000 is the workhorse for general spring and contact use.
- C51000 vs. C26000 cartridge brass — C51000 has dramatically better fatigue and spring performance. C26000 is preferred for deep-drawn, non-spring components.
- C51000 vs. C17200 beryllium copper — C17200 has much higher strength and conductivity but is significantly more expensive. C51000 is the default for general spring contacts; specify C17200 for high-cycle, high-stress applications.
Why Source 21?
- ISO 9001-certified quality system with full chemistry and mechanical traceability on every shipment
- Multi-million dollar national inventory across stainless, nickel alloys, copper, and brass
- Strong domestic and international mill relationships, including premium specialty mill partnerships
- In-house slitting, edging, leveling, and cut-to-length capabilities
- Contract programs, blanket orders, and vendor-managed inventory (VMI) for production accounts
- Responsive technical support for tight-tolerance and certification-driven work
Request a Quote
Contact Source 21 today for C51000 Phosphor Bronze pricing, availability, and processing options. Our team responds quickly, asks the right questions, and gets you accurate quotes on real material — not vague placeholders.
Call 631-821-1101 or request a quote online to get started.