Copper Alloy ZCuZn31Al2
ZCuZn31Al2 is a cast aluminium brass (Cu-Zn with about 2% Al) from the cast brass family, roughly equivalent to EN CC766S.
Reference datasheet — ZCuZn31Al2 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 S condition
ZCuZn31Al2 tempers and conditions
ZCuZn31Al2 is supplied in 4 conditions, soft to hard. S 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 |
|---|---|---|---|---|---|---|
SDefault Sand cast | Standard as-cast sand-mould condition for general marine fittings and medium-size housings. | 125 | 320 | 16 | 65 HB | 22 % IACS |
Centrifugally cast, as-cast | Choose for bushings, sleeves and pump wear rings where a dense, pore-free tubular wall is needed. | 155 | 400 | 18 | 76 HB | 22 % IACS |
Permanent (metal) mould cast, as-cast | Chill-cast condition; finer grain gives noticeably higher strength and ductility for volume production of small marine parts. | 160 | 410 | 20 | 78 HB | 22 % IACS |
Continuously cast bar/tube, as-cast | Continuous-cast bar/tube stock for machined marine bushings and fittings, with directional grain and low porosity. | 160 | 400 | 18 | 78 HB | 22 % IACS |
What is ZCuZn31Al2?
ZCuZn31Al2 is a cast aluminium brass (Cu-Zn with about 2% Al) from the cast brass family, roughly equivalent to EN CC766S. In the default condition it provides 125 MPa yield strength, 320 MPa tensile strength, 16% elongation and about 65 HB, with a corrosion resistance rating of 62, and it is supplied as sand, permanent-mould, centrifugal and continuous castings for marine service. The aluminium content raises seawater resistance but forms an oxide film that complicates welding and gating, and the alloy is not free-cutting. Where machinability matters more than corrosion performance, a leaded cast brass such as ZCuZn38Mn2Pb2 is the nearer choice. ZCuZn31Al2 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 65% of copper alloy grades. It melts at 880°C (1,616 °F). ZCuZn31Al2 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 77% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 98 GPa (14.2 Msi).
What is ZCuZn31Al2 used for?
- marine hardware
- pump impellers
- structural castings
Limitations
- Low stiffness — 98 GPa (14.2 Msi), worse than 86% of copper alloy grades
- Low strength — 125 MPa (18.1 ksi), worse than 77% of copper alloy grades
ZCuZn31Al2 properties
Typical room-temperature values for ZCuZn31Al2-S; bars are the position among copper alloy grades.
Physical3
ZCuZn31Al2 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 65% of copper alloy grades. It melts at 880°C (1,616 °F).
Mechanical15
ZCuZn31Al2 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 77% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 98 GPa (14.2 Msi).
Thermal6
ZCuZn31Al2 is rated for continuous service to 200°C (392 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), better than 54% of copper alloy grades. Thermal expansion is 20 µm/m·K (11.1 µin/in·°F).
Electrical3
ZCuZn31Al2 conducts electricity at 22 % IACS, better than 55% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of ZCuZn31Al2 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 60%.
Manufacturability8
ZCuZn31Al2's machinability is fair (50/100, better than 69% of copper alloy grades); weldability fair (40/100); formability poor (20/100).
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. ZCuZn31Al2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZCuZn31Al2
Is ZCuZn31Al2 easy to machine?
Machines like an unleaded brass — sharp positive-rake carbide, high speed, light feed and good lubrication; chips are stringier than free-cutting C36000 (~40% of AISI 1212).
Can ZCuZn31Al2 be welded?
Weldable by GTAW/GMAW with aluminium-bronze or Al-brass filler, but the alumina film must be removed and zinc fumes controlled; braze/solder only with active flux.
Can ZCuZn31Al2 be formed, bent or molded?
Casting alloy: pour 980–1050 °C with covering flux and degassing, use generous risers and chills; not intended for cold forming.
ZCuZn31Al2 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 |
|---|---|---|
| CuGB/T 1176-2013 | 66 – 68 | 67 |
| Al | 2 – 3 | 2.5 |
| Feimpurity limit | ≤ 0.8 | |
| Siimpurity limit | ≤ 0.05 | |
| Pbimpurity limit | ≤ 1 | |
| Sbimpurity limit | ≤ 0.1 | |
| Snimpurity limit | ≤ 1 | |
| Others (total)total impurities | ≤ 1.5 | |
| Znbalance, about 31% | balance |
What surface finishes work on ZCuZn31Al2?
Polishes to a bright brass finish; can be tin-, nickel- or chrome-plated after careful de-oxidation; not anodizable — protect with lacquer or benzotriazole passivation in marine service.
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 ZCuZn31Al2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- CC766S
How much does ZCuZn31Al2 cost?
ZCuZn31Al2 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.
ZCuZn31Al2 — frequently asked
What is ZCuZn31Al2 used for?
ZCuZn31Al2 is typically used for marine hardware, pump impellers and structural castings. In short: marine-duty cast brass; stronger than plain brass; unleaded, not free-cutting.
What is the yield strength of ZCuZn31Al2?
ZCuZn31Al2 has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 77% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is ZCuZn31Al2 easy to machine?
Reasonably — machinability is rated fair (50/100, better than 69% of copper alloy grades). Machines like an unleaded brass — sharp positive-rake carbide, high speed, light feed and good lubrication; chips are stringier than free-cutting C36000 (~40% of AISI 1212).
Can ZCuZn31Al2 be welded?
With care — weldability is rated fair (40/100). Weldable by GTAW/GMAW with aluminium-bronze or Al-brass filler, but the alumina film must be removed and zinc fumes controlled; braze/solder only with active flux.
What surface finishes work on ZCuZn31Al2?
Polishes to a bright brass finish; can be tin-, nickel- or chrome-plated after careful de-oxidation; not anodizable — protect with lacquer or benzotriazole passivation in marine service.
Can ZCuZn31Al2 be formed, bent or molded?
Casting alloy: pour 980–1050 °C with covering flux and degassing, use generous risers and chills; not intended for cold forming.
What is the maximum service temperature of ZCuZn31Al2?
ZCuZn31Al2 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 ZCuZn31Al2-S and ZCuZn31Al2-J?
S is the default condition — standard as-cast sand-mould condition for general marine fittings and medium-size housings. J: chill-cast condition; finer grain gives noticeably higher strength and ductility for volume production of small marine parts. Yield strength is 125 MPa in S versus 160 MPa in J.
How much does ZCuZn31Al2 cost?
ZCuZn31Al2 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 (CC766S) — CEN (2017)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- CDA copper alloy property data (cast brasses) — Copper Development Association (2023)
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.