Copper Alloy ZCuPb20Sn5
UNS C94100 · EN CC497K
ZCuPb20Sn5 is a high-lead journal bearing bronze with about 20% lead and 5% tin, matching C94100 and CC497K, where the dispersed lead phase provides anti-seizure behaviour and embeddability.
Reference datasheet — ZCuPb20Sn5 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the La condition
ZCuPb20Sn5 tempers and conditions
ZCuPb20Sn5 is supplied in 4 conditions, soft to hard. La is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Sand cast | Choose for large or one-off bearing shells and complex housings where dimensional tolerance is loose. | 60 | 160 | 7 | 48 HB | 10.5 % IACS |
LaDefault Continuously cast bar / tube | Standard stock condition: continuously cast bar and tube for machined high-speed bearing bushings and thrust washers. | 65 | 175 | 9 | 55 HB | 11 % IACS |
Permanent (metal) mould cast | Choose for medium-volume small bushings needing finer grain, less lead segregation and better surface than sand casting. | 68 | 175 | 8 | 57 HB | 11 % IACS |
Centrifugally cast | Choose for large-diameter, thick-wall bearing sleeves and bimetal liners where a dense, inclusion-free bore is required. | 70 | 190 | 8 | 58 HB | 11 % IACS |
What is ZCuPb20Sn5?
ZCuPb20Sn5 is a high-lead journal bearing bronze with about 20% lead and 5% tin, matching C94100 and CC497K, where the dispersed lead phase provides anti-seizure behaviour and embeddability. It is specified for high-speed, lightly loaded journals and connecting-rod bushings, usually as continuous, centrifugal, sand or permanent-mould castings and often on a steel backing. Load capacity is the lowest of the family at 175 MPa tensile, 65 MPa yield, 9% elongation and 55 HB, it is not practically weldable, and lead segregation in thick sections must be controlled. ZCuPb15Sn8 is the nearest higher-strength alternative. ZCuPb20Sn5 has a density of 9.35 g/cm³ (0.338 lb/in³), heavier than 100% of copper alloy grades. It melts at 760°C (1,400 °F). ZCuPb20Sn5 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 175 MPa (25.4 ksi) — weaker than 98% of copper alloy grades. Elongation at break is 9% and the elastic modulus is 72 GPa (10.4 Msi).
What is ZCuPb20Sn5 used for?
- crankshaft bearings
- high-speed journal bearings
- connecting rod bushings
Advantages
- Easy to machine — 92/100, better than 99% of copper alloy grades
Limitations
- Low stiffness — 72 GPa (10.4 Msi), worse than 100% of copper alloy grades
- Low strength — 65 MPa (9.43 ksi), worse than 98% of copper alloy grades
- Difficult to weld — 10/100, worse than 98% of copper alloy grades
- Limited formability — 5/100, worse than 98% of copper alloy grades
- Hard to polish — 55/100, worse than 97% of copper alloy grades
ZCuPb20Sn5 properties
Typical room-temperature values for ZCuPb20Sn5-La; bars are the position among copper alloy grades.
Physical3
ZCuPb20Sn5 has a density of 9.35 g/cm³ (0.338 lb/in³), heavier than 100% of copper alloy grades. It melts at 760°C (1,400 °F).
Mechanical12
ZCuPb20Sn5 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 175 MPa (25.4 ksi) — weaker than 98% of copper alloy grades. Elongation at break is 9% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal6
ZCuPb20Sn5 is rated for continuous service to 200°C (392 °F). It conducts heat at 59 W/m·K (34.1 BTU/hr·ft·°F), worse than 61% of copper alloy grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
ZCuPb20Sn5 conducts electricity at 11 % IACS, worse than 68% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 96% of copper alloy grades.
Sustainability4
Producing a kilogram of ZCuPb20Sn5 takes about 58 MJ of energy and emits 3.6 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 60%.
Manufacturability8
ZCuPb20Sn5's machinability is excellent (92/100, better than 99% of copper alloy grades); weldability not recommended (10/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. ZCuPb20Sn5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZCuPb20Sn5
Is ZCuPb20Sn5 easy to machine?
Free-cutting: use sharp positive-rake tools, high speed, light feed and flood coolant; chips are short and lead dust requires extraction — avoid excessive burnishing of the soft bore.
Can ZCuPb20Sn5 be welded?
Not practically weldable — lead causes hot cracking and porosity; join by mechanical press-fit, sintering to a steel backing, or soft soldering only.
Can ZCuPb20Sn5 be formed, bent or molded?
Casting-only alloy (sand, metal mould, continuous or centrifugal); pour with controlled cooling and stirring/chill to keep lead finely dispersed and avoid gravity segregation in thick sections.
ZCuPb20Sn5 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Sn | 4 – 6 | 5 |
| Pbfree lead phase provides lubricity/embeddability | 18 – 23 | 20 |
| Znimpurity limit | ≤ 2 | |
| Feimpurity limit | ≤ 0.25 | |
| Sbimpurity limit | ≤ 0.75 | |
| Pimpurity limit | ≤ 0.1 | |
| Cu≈74–78 %; total impurities ≤1.0 % per GB/T 1176 | balance |
What surface finishes work on ZCuPb20Sn5?
Bore honed or diamond-burnished for bearing surfaces; can be tin- or silver-plated for anti-fretting, but not anodized; chemical blackening possible.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Copper Alloy ZCuPb20Sn5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does ZCuPb20Sn5 cost?
ZCuPb20Sn5 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZCuPb20Sn5 — frequently asked
What is ZCuPb20Sn5 used for?
ZCuPb20Sn5 is typically used for crankshaft bearings, high-speed journal bearings and connecting rod bushings. In short: highest-lead journal bronze; best anti-seizure bearing grade; lowest strength in family.
What is the yield strength of ZCuPb20Sn5?
ZCuPb20Sn5 has a typical yield strength of 65 MPa (9.43 ksi) and a tensile strength of 175 MPa (25.4 ksi) — weaker than 98% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is ZCuPb20Sn5 easy to machine?
Yes — machinability is rated excellent (92/100, better than 99% of copper alloy grades). Free-cutting: use sharp positive-rake tools, high speed, light feed and flood coolant; chips are short and lead dust requires extraction — avoid excessive burnishing of the soft bore.
Can ZCuPb20Sn5 be welded?
Not readily — weldability is rated not recommended (10/100). Not practically weldable — lead causes hot cracking and porosity; join by mechanical press-fit, sintering to a steel backing, or soft soldering only.
What surface finishes work on ZCuPb20Sn5?
Bore honed or diamond-burnished for bearing surfaces; can be tin- or silver-plated for anti-fretting, but not anodized; chemical blackening possible.
Can ZCuPb20Sn5 be formed, bent or molded?
Casting-only alloy (sand, metal mould, continuous or centrifugal); pour with controlled cooling and stirring/chill to keep lead finely dispersed and avoid gravity segregation in thick sections.
What is the maximum service temperature of ZCuPb20Sn5?
ZCuPb20Sn5 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZCuPb20Sn5-La and ZCuPb20Sn5-S?
La is the default condition — standard stock condition: continuously cast bar and tube for machined high-speed bearing bushings and thrust washers. S: choose for large or one-off bearing shells and complex housings where dimensional tolerance is loose. Yield strength is 65 MPa in La versus 60 MPa in S.
How much does ZCuPb20Sn5 cost?
ZCuPb20Sn5 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 1982 Copper and copper alloys — Ingots and castings (CC497K CuPb20Sn5-C) — CEN (2017)
- ASTM B505/B505M Continuous-Cast Copper Alloys (C94100) — ASTM (2018)
- CDA alloy datasheet C94100 — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties of Cast Copper Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.