Copper Alloy CC761S
EN CC761S
CC761S (CuZn16Si4-C, C87500) is a silicon brass casting alloy in which the Cu-Si phase provides strength and corrosion resistance without lead, making it a lead-free substitute for plumbing brasses.
Reference datasheet — CC761S 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 GM condition
CC761S tempers and conditions
CC761S is supplied in 5 conditions, soft to hard. GM is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Sand cast | Choose for larger or one-off valve/pump bodies where tooling cost must stay low. | 240 | 440 | 12 | 105 HB | 6.7 % IACS |
Investment / precision cast | Pick for complex near-net-shape parts with tight tolerance and fine surface where machining access is poor. | 255 | 490 | 11 | 115 HB | 6.7 % IACS |
GMDefault Gravity die (permanent mould) cast | Standard choice for series-produced lead-free plumbing fittings and valve bodies needing pressure tightness. | 260 | 500 | 12 | 115 HB | 6.7 % IACS |
Centrifugally cast | Use for bushings, sleeves and rings where a dense, inclusion-free rotationally symmetric part is needed. | 260 | 500 | 12 | 115 HB | 6.7 % IACS |
Continuously cast bar/tube | Stocked bar and hollow form for machined fittings and small pressure parts; finest structure and best consistency. | 280 | 520 | 12 | 120 HB | 6.9 % IACS |
What is CC761S?
CC761S (CuZn16Si4-C, C87500) is a silicon brass casting alloy in which the Cu-Si phase provides strength and corrosion resistance without lead, making it a lead-free substitute for plumbing brasses. Default-condition properties are 260 MPa yield, 500 MPa tensile, 12 % elongation and 115 HB, and it casts pressure-tight thin sections by sand (GS), permanent-mould (GM), centrifugal (GZ), continuous (GC) and pressure die (GP) routes. It machines at roughly half the rate of free-cutting leaded brass and the hard silicon particles shorten tool life; where machinability matters more than lead-free status, CC754S is the alternative. CC761S has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F). CC761S has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 96 GPa (13.9 Msi).
What is CC761S used for?
- potable water fittings
- marine hardware
- pump components
Advantages
- Low embodied carbon — 3.2 kg CO₂/kg, better than 92% of copper alloy grades
Limitations
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades
- Low stiffness — 96 GPa (13.9 Msi), worse than 91% of copper alloy grades
- Low electrical conductivity — 6.7 % IACS, worse than 89% of copper alloy grades
- Limited formability — 15/100, worse than 79% of copper alloy grades
CC761S properties
Typical room-temperature values for CC761S-GM; bars are the position among copper alloy grades.
Physical3
CC761S has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F).
Mechanical15
CC761S has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 96 GPa (13.9 Msi).
Thermal6
CC761S is rated for continuous service to 200°C (392 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades. Thermal expansion is 19.6 µm/m·K (10.9 µin/in·°F).
Electrical3
CC761S conducts electricity at 6.7 % IACS, worse than 89% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (63/100), better than 52% of copper alloy grades.
Sustainability4
Producing a kilogram of CC761S takes about 45 MJ of energy and emits 3.2 kg of CO₂ — less than 97% of copper alloy grades. Typical recycled content is 80%.
Manufacturability8
CC761S's machinability is good (55/100, better than 71% of copper alloy grades); weldability fair (45/100); formability poor (15/100).
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. CC761S is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CC761S
Is CC761S easy to machine?
Machines at roughly half the rate of free-cutting leaded brass — use sharp carbide, positive rake, good coolant; hard Cu-Si particles accelerate tool wear and chips are gummy.
Can CC761S be welded?
GTAW/GMAW with silicon-bronze filler is possible but the tenacious silicon oxide film and hot-shortness demand a good flux/shield and low heat input; repair welding of castings should be pre-heated ~150 °C.
Can CC761S be formed, bent or molded?
Casting alloy only: excellent fluidity and low shrinkage porosity give pressure-tight thin sections in sand, gravity-die, centrifugal and continuous casting; not cold formable.
CC761S 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 | 78 – 82 | 80 |
| Siforms hard Cu-Si phase, gives fluidity and strength | 3 – 5 | 4 |
| Pblow-lead / lead-free potable-water grades often limited to ≤0.09–0.1 % | ≤ 0.3 | 0.1 |
| Fe | ≤ 0.4 | 0.15 |
| Al | ≤ 0.1 | 0.05 |
| Mn | ≤ 0.5 | 0.1 |
| Ni | ≤ 0.5 | 0.1 |
| Sn | ≤ 0.3 | 0.1 |
| Znnominally ~16 % | balance |
What surface finishes work on CC761S?
Polishes and buffs well; pickle to remove SiO2 before Ni/Cr plating or soldering, and passivate/rinse for potable-water 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 CC761S in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- CuZn16Si4-C
- Similar grades
- C87500
How much does CC761S cost?
CC761S 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.
CC761S — frequently asked
What is CC761S used for?
CC761S is typically used for potable water fittings, marine hardware and pump components. In short: lead-free plumbing brass; pressure-tight castings; 500 MPa cast tensile.
What is the yield strength of CC761S?
CC761S has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is CC761S easy to machine?
Reasonably — machinability is rated good (55/100, better than 71% of copper alloy grades). Machines at roughly half the rate of free-cutting leaded brass — use sharp carbide, positive rake, good coolant; hard Cu-Si particles accelerate tool wear and chips are gummy.
Can CC761S be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW with silicon-bronze filler is possible but the tenacious silicon oxide film and hot-shortness demand a good flux/shield and low heat input; repair welding of castings should be pre-heated ~150 °C.
What surface finishes work on CC761S?
Polishes and buffs well; pickle to remove SiO2 before Ni/Cr plating or soldering, and passivate/rinse for potable-water service.
Can CC761S be formed, bent or molded?
Casting alloy only: excellent fluidity and low shrinkage porosity give pressure-tight thin sections in sand, gravity-die, centrifugal and continuous casting; not cold formable.
What is the maximum service temperature of CC761S?
CC761S 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 CC761S-GM and CC761S-GS?
GM is the default condition — standard choice for series-produced lead-free plumbing fittings and valve bodies needing pressure tightness. GS: choose for larger or one-off valve/pump bodies where tooling cost must stay low. Yield strength is 260 MPa in GM versus 240 MPa in GS.
How much does CC761S cost?
CC761S 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 (CuZn16Si4-C / CC761S) — CEN (2017)
- ASTM B584 — Copper Alloy Sand Castings for General Applications (C87500) — ASTM (2022)
- CDA Alloy Datasheet C87500 Silicon Brass — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous 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.