Copper Alloy CC761S-GC (Continuously cast bar/tube)
Finish state
EN CC761S
Stocked bar and hollow form for machined fittings and small pressure parts; finest structure and best consistency.
Values for the GC condition
Other CC761S tempers and conditions
CC761S is listed in 5 conditions; see the grade overview at CC761S.
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 |
GCThis page 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-GC?
CC761S-GC is CC761S supplied in the GC condition — stocked bar and hollow form for machined fittings and small pressure parts; finest structure and best consistency. CC761S-GC has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 97 GPa (14.1 Msi). CC761S-GC 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). GM is the default condition FabDigit quotes; GC is available on request or by drawing note.
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 — 97 GPa (14.1 Msi), worse than 88% of copper alloy grades
- Low electrical conductivity — 6.9 % IACS, worse than 88% of copper alloy grades
- Limited formability — 18/100, worse than 75% of copper alloy grades
CC761S-GC properties
Typical room-temperature values for CC761S-GC; 21 are specific to this condition. Other listed values are CC761S reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CC761S-GC 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-GC has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
CC761S-GC 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-GC conducts electricity at 6.9 % IACS, worse than 88% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (64/100), better than 52% of copper alloy grades.
Sustainability4
Producing a kilogram of CC761S-GC 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-GC's machinability is good (57/100, better than 73% of copper alloy grades); weldability fair (45/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CC761S-GC
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.
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.
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 | — |
CC761S-GC — frequently asked
What is CC761S-GC used for?
CC761S-GC 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-GC?
CC761S-GC has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 59% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is CC761S-GC easy to machine?
Reasonably — machinability is rated good (57/100, better than 73% 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-GC 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-GC?
Polishes and buffs well; pickle to remove SiO2 before Ni/Cr plating or soldering, and passivate/rinse for potable-water service.
Can CC761S-GC 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-GC?
CC761S-GC 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.