Copper Alloy ZCuZn31Al2-S (Sand cast)
Heat-treated state · default condition
Standard as-cast sand-mould condition for general marine fittings and medium-size housings.
Values for the S condition
Other ZCuZn31Al2 tempers and conditions
ZCuZn31Al2 is listed in 4 conditions; see the grade overview at ZCuZn31Al2.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SDefaultThis page 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-S?
ZCuZn31Al2-S is ZCuZn31Al2 heat treated to S — standard as-cast sand-mould condition for general marine fittings and medium-size housings. ZCuZn31Al2-S 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). ZCuZn31Al2-S 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).
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-S properties
Typical room-temperature values for ZCuZn31Al2-S; 21 are specific to this condition. Other listed values are ZCuZn31Al2 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
ZCuZn31Al2-S 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-S 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-S 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-S 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-S 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'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. Confirm any required mill or lot documentation when quoting.
Working with ZCuZn31Al2-S
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.
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.
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 | — |
ZCuZn31Al2-S — frequently asked
What is ZCuZn31Al2-S used for?
ZCuZn31Al2-S 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-S?
ZCuZn31Al2-S 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-S 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-S 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-S?
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-S 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-S?
ZCuZn31Al2-S 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.