Copper Alloy CC381H-GC (Continuously cast)
Finish state
EN CC381H · UNS C96400
Bar/tube stock condition for machined fittings and valve components; uniform, low-porosity structure.
Values for the GC condition
Other CC381H tempers and conditions
CC381H is listed in 4 conditions; see the grade overview at CC381H.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
GSDefault Sand cast | Standard supply condition for pump casings, valve bodies and large marine housings. | 255 | 470 | 25 | 140 HB | 4.6 % IACS |
Gravity (permanent mould) die cast | Choose for medium-run small parts needing finer grain and better surface than sand casting. | 265 | 485 | 22 | 145 HB | 4.6 % IACS |
GCThis page Continuously cast | Bar/tube stock condition for machined fittings and valve components; uniform, low-porosity structure. | 270 | 490 | 20 | 148 HB | 4.6 % IACS |
Centrifugally cast | Best choice for seawater pipe, sleeves, wear rings and bushings — densest, most sound structure. | 275 | 500 | 20 | 150 HB | 4.6 % IACS |
What is CC381H-GC?
CC381H-GC is CC381H supplied in the GC condition — bar/tube stock condition for machined fittings and valve components; uniform, low-porosity structure. CC381H-GC has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 56% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 151 GPa (21.9 Msi). CC381H-GC has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 77% of copper alloy grades. It melts at 1,170°C (2,138 °F). GS is the default condition FabDigit quotes; GC is available on request or by drawing note.
Advantages
- Stiff — 151 GPa (21.9 Msi), better than 98% of copper alloy grades
- Good corrosion resistance — 82/100, better than 98% of copper alloy grades
- Readily welded — 78/100, better than 91% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% 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 electrical conductivity — 4.6 % IACS, worse than 96% of copper alloy grades
- High embodied carbon — 6 kg CO₂/kg, worse than 92% of copper alloy grades
CC381H-GC properties
Typical room-temperature values for CC381H-GC; 20 are specific to this condition. Other listed values are CC381H reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CC381H-GC has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 77% of copper alloy grades. It melts at 1,170°C (2,138 °F).
Mechanical13
CC381H-GC has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 56% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 151 GPa (21.9 Msi).
Thermal6
CC381H-GC is rated for continuous service to 300°C (572 °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 15.3 µm/m·K (8.5 µin/in·°F).
Electrical3
CC381H-GC conducts electricity at 4.6 % IACS, worse than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of CC381H-GC takes about 75 MJ of energy and emits 6 kg of CO₂ — more than 88% of copper alloy grades. Typical recycled content is 40%.
Manufacturability6
CC381H-GC's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability very good (78/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CC381H-GC
Is CC381H easy to machine?
Gummy and work-hardening like all Cu-Ni: use sharp positive-rake carbide, low speed (~30–60 m/min) with heavy positive feed, rigid setup and abundant coolant; avoid dwelling to prevent glazing.
Can CC381H be welded?
Good weldability with GTAW/GMAW using 70/30 Cu-Ni (ERCuNi) or Ni-Cu filler; keep interpass temperature low, no preheat needed, and remove all oxide/sulphur contamination before welding.
Can CC381H be formed, bent or molded?
Cast-only grade: long freezing range demands large risers, chills and directional solidification; deoxidise with Mn/Si and keep melt free of C, S, Pb to avoid porosity and hot tearing.
What surface finishes work on CC381H?
Takes a fine polish and develops a protective brown-green patina in seawater; no anodising — use pickling/passivation or leave bare, and avoid galvanic coupling with steel without insulation or cathodic protection.
CC381H 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 |
|---|---|---|
| Niincludes Co | 29 – 32 | 30 |
| Fecorrosion/erosion resistance | 0.5 – 1.5 | 1 |
| Mndeoxidiser | 0.5 – 1.5 | 1 |
| Nbadded to control weld/casting soundness (C96400 requires Nb) | 0.5 – 1 | 0.7 |
| Sideoxidiser, max | ≤ 0.5 | 0.2 |
| C | ≤ 0.1 | — |
| Zn | ≤ 0.5 | — |
| Pbmax; embrittling | ≤ 0.01 | — |
| S | ≤ 0.02 | — |
| P | ≤ 0.02 | — |
| Curemainder, approx. 64–69 % | balance | — |
CC381H-GC — frequently asked
What is CC381H-GC used for?
CC381H-GC is typically used for marine pump housings, propeller hubs, condenser end covers and seawater piping fittings. In short: stronger than cast 90-10; high-velocity seawater service; weldable cast Cu-Ni.
What is the yield strength of CC381H-GC?
CC381H-GC has a typical yield strength of 270 MPa (39.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 56% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is CC381H-GC easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Gummy and work-hardening like all Cu-Ni: use sharp positive-rake carbide, low speed (~30–60 m/min) with heavy positive feed, rigid setup and abundant coolant; avoid dwelling to prevent glazing.
Can CC381H-GC be welded?
Yes — weldability is rated very good (78/100). Good weldability with GTAW/GMAW using 70/30 Cu-Ni (ERCuNi) or Ni-Cu filler; keep interpass temperature low, no preheat needed, and remove all oxide/sulphur contamination before welding.
What surface finishes work on CC381H-GC?
Takes a fine polish and develops a protective brown-green patina in seawater; no anodising — use pickling/passivation or leave bare, and avoid galvanic coupling with steel without insulation or cathodic protection.
Can CC381H-GC be formed, bent or molded?
Cast-only grade: long freezing range demands large risers, chills and directional solidification; deoxidise with Mn/Si and keep melt free of C, S, Pb to avoid porosity and hot tearing.
What is the maximum service temperature of CC381H-GC?
CC381H-GC is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CC381H-GS and CC381H-GZ?
GS is the default condition — standard supply condition for pump casings, valve bodies and large marine housings. GZ: best choice for seawater pipe, sleeves, wear rings and bushings — densest, most sound structure. Yield strength is 255 MPa in GS versus 275 MPa in GZ.
Sources
- EN 1982 — Copper and copper alloys: ingots and castings (CuNi30Fe1Mn1-C, CC381H) — CEN (2017)
- ASTM B369 — Copper-Nickel Alloy Castings — ASTM International (2021)
- C96400 alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Copper-Nickel Alloys: Properties and Applications (Pub. 12007) — Nickel Institute / CDA (2016)
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.