C51000 - Copper Alloys

C51000 tin phosphor bronze (CuSn5P)

C51000 is a wrought 5% tin phosphor bronze (CuSn5P) supplied to specifications including ASTM B139 Alloy A and AMS 4625. This alloy is one of the most widely used phosphor bronzes, offering a well-balanced combination of strength, ductility, and fatigue resistance.

The addition of tin enhances mechanical strength and corrosion resistance, while phosphorus improves wear resistance, stiffness, and fatigue performance. This allows C51000 to be supplied in a range of tempers, from soft to hard and spring conditions, enabling engineers to tailor the material for applications requiring either higher ductility or increased tensile strength.

C51000 also exhibits excellent cold working characteristics, good bearing properties, and a low coefficient of friction, making it particularly suitable for moving or load-bearing components. Its combination of corrosion resistance and mechanical performance means it performs reliably in both industrial and moderately aggressive environments.

Typical equivalent specifications include ASTM B103, ASTM B100, AMS 4510, SAE J461, SAE J463, and CW450K, all of which refer to similar CuSn5 phosphor bronze compositions used across aerospace, electrical, and general engineering applications

For a full comparison of phosphor bronze and alternative copper alloys, use the alloy selector tool.

Equivalent Specifications

ASTM B139 C51000
ASTM B103 C51000
ASTM B100 C51000
AMS 4625
ASTM F 468
AMS 4510
SAE J461
> SAE J463
CW450K

Key Features

A single alpha phase copper tin alloy with a small addition of phosphorus.

The alloy offers a good combination of cold working properties, strength and hardness. It has good resistance to corrosion, including stress corrosion.

Typical Uses

Architectural: masonry fittings.

Electrical: springs, clips, switch components and contacts.

Mechanical: cold headed screws, rivets, bolts, nuts, washers and cotter pins.

Bearing and expansion plates for bridges and other structural applications.

Description	Phosphor Bronze
Nominal Composition	CuSn5P
Alloy Type	wrought

Typical Mechanical Properties

Tensile Strength (N/mm²)	485
Proof/Yield Strength (N/mm²)	400
Elongation (%)	25
Hardness Brinell	78
Impact Izod J20°C

Typical Physical Properties

Density g/cm³	8.86
Melting Temperature Range °C	950 - 1050
Thermal Conductivity W/mK	69
Electrical Resistivity μΩ.m15°C	11.5
Coefficient of Thermal Expansion 0-250°C	17.8
Relative Magnetic Permeability	1.01
Coefficient of Friction

Copper Alloys has the ability to modify existing alloys for improved performance. Many customers have benefited from this in the past.

To discuss your requirements, call a member of Copper Alloys’s technical team on +44 (0) 1782-816888, or email [email protected].

This Data is indicative only and must not be seen as a substitute for the full specification from which it is drawn. In particular, the mechanical property requirements vary widely with tempeter, product and product dimensions. The information is based on our present knowledge and is given in good faith. However, no liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose.

Any advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. Any contract between the Company and a customer will be subject to the Company’s Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions, a copy of which is available on request.