PB4 Phosphor Bronze Alloy

PB4 (CuSn10PbP) is a continuous cast phosphor bronze alloy designed for demanding bearing and gear applications where a combination of strength, wear resistance and machinability is required. Similar to PB1 but with the addition of lead, PB4 offers improved machining performance and enhanced anti-friction properties, making it well suited to components operating under medium to high loads. Conforming to BS1400, this alloy performs reliably in applications such as gears, bushings and bearings, where it can accommodate high speeds, shock loading and impact conditions, provided effective lubrication and correct alignment are maintained.

Alternative Alloys

PB4 (CuSn10PbP) is equivalent to international grades such as CC481K and ASTM C90700, with similar mechanical properties and wear resistance characteristics. It belongs to the phosphor bronze family alongside PB1 and PB2, which may be selected depending on machinability and load requirements. For alternative bearing applications, leaded bronzes such as SAE 660 may be considered where improved anti-friction performance is required. See our alloy selector for these and other alloys.

Equivalent Specifications

BS EN 1982-2008 GC CC481K
CuSn11P-C
ASTM B 505 C90700
QQ-C-390
SAE J461
SAE J462
SAE 65C

Key Features

PB4 shows good shock resistance and strength combined with low friction properties and good general corrosion resistance.

Typical Uses

PB4 is typically used for gears, bearings, bushings, wear / slide plates, worm wheels with hard shafts, requiring high loads, high speeds and impact loading with adequate lubrication and good alignment.

Description	Phosphor Bronze
Nominal Composition	CuSn10PbP
Alloy Type	cast

Typical Mechanical Properties

Tensile Strength (N/mm²)	360
Proof/Yield Strength (N/mm²)	180
Elongation (%)	15
Hardness Brinell	100
Impact Izod J20°C

Typical Physical Properties

Density g/cm³	8.8
Melting Temperature Range °C	831 - 1000
Thermal Conductivity W/mK	47
Electrical Resistivity μΩ.m15°C	0.17
Coefficient of Thermal Expansion 0-250°C	18
Relative Magnetic Permeability
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.