CuPb9Sn5

What Is CuSn5Pb9?

CuSn5Pb9 is a copper-tin bearing bronze with a relatively high lead content. Under EN 1982 the casting grade is CuSn5Pb9-C / CC494K and the related ingot grade is CuSn5Pb9-B / CB494K. Çorum Bronz produces and supplies it under the trade name KUPTİN® PB9.

About 4-6% tin supports strength and wear behaviour, while 8-10% lead improves sliding properties, conformability, embeddability of small foreign particles and machinability. It is particularly suited to bearing systems operating at moderate loads with appropriate lubrication.

Chemical Composition

For CuSn5Pb9-C / CC494K castings, Cu including Ni is 80.0-87.0%, Sn 4.0-6.0% and Pb 8.0-10.0%. Zn and Ni are limited to 2.0% max.; Fe 0.25%; Mn 0.20%; P and S 0.10%; Sb 0.50%; and Al and Si 0.01% max. The copper figure includes nickel. The ingot CB494K and casting CC494K limits must not be treated as identical; final compliance should be checked against the product certificate.

Mechanical Properties

Process-specific minimum references are: sand casting (GS) Rm 160 MPa, Rp0.2 60 MPa, A 7% and 55 HBW; permanent mould casting (GM) 200 MPa, 80 MPa, 5% and 60 HBW; centrifugal casting (GZ) 200 MPa, 90 MPa, 6% and 60 HBW; continuous casting (GC) 200 MPa, 100 MPa, 9% and 60 HBW. Actual components can vary with section, sampling location and casting structure.

Typical Physical Properties

Typical references include density around 8.9-9.0 g/cm³, melting range about 844-1000 °C, thermal conductivity around 71 W/(m·K) and thermal expansion around 18 × 10⁻⁶/K. These are typical data, not guaranteed EN 1982 acceptance values.

Çorum Bronz Technical Assessment

CuSn5Pb9 combines good sliding behaviour, embeddability, suitable wear resistance and excellent machinability. It is commonly considered for medium loads and moderate-to-high sliding speeds. The lead phase can improve tolerance to short lubrication deficiencies, but the alloy should not be described as inherently self-lubricating or maintenance-free.

Bearing and bushing design should consider surface pressure, speed, lubrication, shaft hardness, surface finish, running clearance, temperature, alignment and contamination risk together.

Applications

Typical applications include medium-duty plain bearings and bushings, electric-motor and packaging-machine bearings, crane and elevator bearings, small machine-tool bearings, hydraulic-cylinder guide bushes, valve and gate seat rings, slip rings, pump components and general machine bearing parts.

Production Technology and Product Forms

KUPTİN® PB9 may be produced by sand, permanent mould, centrifugal and continuous casting. The process is selected according to geometry, section, quantity, mechanical requirements and purchase specification.

Supply forms include hollow bronze bar / tube, solid round bar, flat / plate, bushing blanks and project-specific castings.

Production, Sales and Supply from Çorum Bronz

Çorum Bronz serves not only as a producer of CuSn5Pb9-C / CC494K but also as a metal supplier through its Metal Market. Standard or available sizes, cut lengths, hollow bronze products, round bars, flats and plates can be supplied, while non-standard dimensions and geometries can be produced as project-specific castings.

Purchasing and Quotation

Price and lead time depend on product form, diameter and section, inside and outside diameter, length, quantity, casting process, cutting requirements and requested quality documentation. Current stock, producible sizes, lead time and quotation can be requested from Çorum Bronz.

Standards and Comparable Grades

The principal European casting designation is CuSn5Pb9-C / CC494K, with CuSn5Pb9-B / CB494K as the related ingot grade. BS 1400 LB4 and UNS C93500 / SAE 66 are close comparisons rather than automatic exact equivalents. ASTM B505/B505M covers continuous-cast products, ASTM B271/B271M centrifugal castings and ASTM B584 copper-alloy castings; C93500 is a UNS alloy number, not an ASTM grade name.

ISO 4382-1:2021 / CuPb9Sn5 is the current application standard for solid and multilayer thick-walled plain bearings. CuPb9Sn5 under ISO 1338:1977 is a historical comparison and that standard has been withdrawn. No reliable direct former DIN grade number has been verified for CuSn5Pb9, so an old DIN code should not be stated as an exact equivalent without documentary confirmation.

Engineering and Regulatory Note

Final product properties should be verified against the purchase specification, selected standard, casting process, section, dimensions, tolerances, production lot, chemical analysis and quality-control results. Because the alloy contains 8-10% lead, drinking-water, food-contact or other regulated applications require separate verification of approvals and lead-release requirements.