Copper Alloy ZCuZn16Si4-La
Finish state
La = continuously cast bar/tube
Pick for machined-from-bar fittings and bushings needing uniform fine structure and best pressure tightness.
Values for the La condition
Other ZCuZn16Si4 tempers and conditions
ZCuZn16Si4 is listed in 4 conditions; see the grade overview at ZCuZn16Si4.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SDefault Sand cast | Default condition for valve bodies, pump housings and fittings poured in green/resin sand. | 200 | 380 | 18 | 100 HB | 7 % IACS |
Permanent (metal) mould cast, as-cast | Choose for higher strength and ductility in repeat-production small/medium parts poured in iron dies. | 230 | 420 | 22 | 110 HB | 7 % IACS |
Centrifugally cast | Use for bushings, sleeves and rings where a dense, inclusion-free rotational casting is needed. | 230 | 420 | 20 | 110 HB | 7 % IACS |
LaThis page Continuously cast bar/tube | Pick for machined-from-bar fittings and bushings needing uniform fine structure and best pressure tightness. | 240 | 430 | 16 | 115 HB | 7 % IACS |
What is ZCuZn16Si4-La?
ZCuZn16Si4-La is ZCuZn16Si4 supplied in the La condition — pick for machined-from-bar fittings and bushings needing uniform fine structure and best pressure tightness. ZCuZn16Si4-La has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 52% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 100 GPa (14.5 Msi). ZCuZn16Si4-La has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F). S is the default condition FabDigit quotes; La is available on request or by drawing note.
Advantages
- Good corrosion resistance — 72/100, better than 84% of copper alloy grades
Limitations
- Poor heat conductor — 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades
- Low electrical conductivity — 7 % IACS, worse than 86% of copper alloy grades
- Low stiffness — 100 GPa (14.5 Msi), worse than 82% of copper alloy grades
ZCuZn16Si4-La properties
Typical room-temperature values for ZCuZn16Si4-La; 21 are specific to this condition. Other listed values are ZCuZn16Si4 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
ZCuZn16Si4-La has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F).
Mechanical15
ZCuZn16Si4-La has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 52% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
ZCuZn16Si4-La is rated for continuous service to 200°C (392 °F). It conducts heat at 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades. Thermal expansion is 19 µm/m·K (10.6 µin/in·°F).
Electrical3
ZCuZn16Si4-La conducts electricity at 7 % IACS, worse than 86% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 84% of copper alloy grades.
Sustainability4
Producing a kilogram of ZCuZn16Si4-La takes about 60 MJ of energy and emits 3.6 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 70%.
Manufacturability8
ZCuZn16Si4-La's machinability is fair (45/100, better than 64% of copper alloy grades); weldability fair (40/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZCuZn16Si4-La
Is ZCuZn16Si4 easy to machine?
Machines to a rating of about 50 % of free-cutting brass — use sharp carbide, positive rake and generous coolant; silicides cause tool wear and gummy chips at low speed.
Can ZCuZn16Si4 be welded?
TIG/oxy-fuel repair possible with silicon-bronze filler and preheat 150–250 °C, but the alloy is hot-short and prone to porosity; avoid welded pressure boundaries where possible.
Can ZCuZn16Si4 be formed, bent or molded?
A casting alloy only: excellent fluidity fills 2–3 mm walls, so use directional solidification and moderate risers; pour 980–1050 °C and avoid excessive superheat to limit Si oxide dross.
What surface finishes work on ZCuZn16Si4?
Not anodizable; degrease and pickle to remove the tenacious Si-rich oxide before nickel/chrome or tin plating, or buff and lacquer for decorative parts.
ZCuZn16Si4 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 |
|---|---|---|
| Cu | 79 – 81 | 80 |
| Si | 2.5 – 4.5 | 3.5 |
| Feimpurity limit | ≤ 0.6 | — |
| Alimpurity limit | ≤ 0.1 | — |
| Mnimpurity limit | ≤ 0.5 | — |
| Pbimpurity limit | ≤ 0.5 | — |
| Snimpurity limit | ≤ 0.3 | — |
| Sbimpurity limit | ≤ 0.1 | — |
| impurities totalsum of impurities per GB/T 1176 | ≤ 2 | — |
| Zn | balance | — |
ZCuZn16Si4-La — frequently asked
What is ZCuZn16Si4-La used for?
ZCuZn16Si4-La is typically used for water valves, pump housings and marine fittings. In short: strongest cast brass here; lead-free pressure-tight castings; harder on tooling.
What is the yield strength of ZCuZn16Si4-La?
ZCuZn16Si4-La has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 52% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is ZCuZn16Si4-La easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Machines to a rating of about 50 % of free-cutting brass — use sharp carbide, positive rake and generous coolant; silicides cause tool wear and gummy chips at low speed.
Can ZCuZn16Si4-La be welded?
With care — weldability is rated fair (40/100). TIG/oxy-fuel repair possible with silicon-bronze filler and preheat 150–250 °C, but the alloy is hot-short and prone to porosity; avoid welded pressure boundaries where possible.
What surface finishes work on ZCuZn16Si4-La?
Not anodizable; degrease and pickle to remove the tenacious Si-rich oxide before nickel/chrome or tin plating, or buff and lacquer for decorative parts.
Can ZCuZn16Si4-La be formed, bent or molded?
A casting alloy only: excellent fluidity fills 2–3 mm walls, so use directional solidification and moderate risers; pour 980–1050 °C and avoid excessive superheat to limit Si oxide dross.
What is the maximum service temperature of ZCuZn16Si4-La?
ZCuZn16Si4-La 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 ZCuZn16Si4-S and ZCuZn16Si4-La?
S is the default condition — default condition for valve bodies, pump housings and fittings poured in green/resin sand. La: pick for machined-from-bar fittings and bushings needing uniform fine structure and best pressure tightness. Yield strength is 200 MPa in S versus 240 MPa in La.
Sources
- EN 1982 Copper and copper alloys — Ingots and castings (CC761S) — CEN (2017)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- CDA alloy datasheet C87500 silicon brass — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.