Copper Alloy C77000-H02
Supply condition · default condition
UNS C77000 · EN CW410J
H02 = half hard
Most widely stocked strip/sheet temper: good balance of strength, formability and flatness for hardware and contacts.
Values for the H02 condition
Other C77000 tempers and conditions
C77000 is listed in 8 conditions; see the grade overview at C77000.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.035 mm grain size | Softest commercial condition for deep drawing, spinning and severe forming before final work-hardening. | 186 | 414 | 40 | 100 HB | 5.7 % IACS |
As hot rolled | Hot-rolled plate/bar stock for subsequent machining or forming where temper is not critical. | 205 | 435 | 35 | 62 HRB | — |
Quarter hard | Light cold work when moderate strength must be combined with continued bending and drawing ability. | 400 | 483 | 25 | 76 HRB | — |
H02DefaultThis page Half hard | Most widely stocked strip/sheet temper: good balance of strength, formability and flatness for hardware and contacts. | 505 | 565 | 12 | 84 HRB | — |
Full hard | High-strength flat stock for stamped parts with only gentle bends, and for wear-resistant decorative trim. | 585 | 655 | 4 | 89 HRB | — |
Extra hard | Use where near-spring strength is needed but full spring temper flatness is not required. | 655 | 725 | 3 | 92 HRB | — |
Spring hard | Standard choice for flat springs, contact fingers and diaphragms needing maximum elastic limit with good tarnish resistance. | 710 | 790 | 2 | 95 HRB | — |
Extra spring hard | Maximum-strength strip for thin, highly stressed springs formed with very generous bend radii only. | 745 | 825 | 2 | 19 HRC | 5.3 % IACS |
What is C77000-H02?
C77000-H02 is C77000 supplied in the H02 condition — most widely stocked strip/sheet temper: good balance of strength, formability and flatness for hardware and contacts. C77000-H02 has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 565 MPa (81.9 ksi) — stronger than 90% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 124 GPa (18 Msi). C77000-H02 has a density of 8.72 g/cm³ (0.315 lb/in³), lighter than 54% of copper alloy grades. It melts at 1,010°C (1,850 °F).
Advantages
- Polishes to a fine finish — 90/100, better than 99% of copper alloy grades
- High strength — 505 MPa (73.2 ksi), better than 90% of copper alloy grades
Limitations
- Low electrical conductivity — 5.5 % IACS, worse than 95% of copper alloy grades
- Poor heat conductor — 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades
- Limited service temperature — 175°C (347 °F), worse than 92% of copper alloy grades
- High embodied carbon — 5.6 kg CO₂/kg, worse than 91% of copper alloy grades
C77000-H02 properties
Typical room-temperature values for C77000-H02; 10 are specific to this condition. Other listed values are C77000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C77000-H02 has a density of 8.72 g/cm³ (0.315 lb/in³), lighter than 54% of copper alloy grades. It melts at 1,010°C (1,850 °F).
Mechanical12
C77000-H02 has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 565 MPa (81.9 ksi) — stronger than 90% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C77000-H02 is rated for continuous service to 175°C (347 °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 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C77000-H02 conducts electricity at 5.5 % IACS, worse than 95% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C77000-H02 takes about 78 MJ of energy and emits 5.6 kg of CO₂ — more than 90% of copper alloy grades. Typical recycled content is 35%.
Manufacturability7
C77000-H02's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability fair (40/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C77000-H02
Is C77000 easy to machine?
Tough and gummy (≈20% of free-cutting brass) — use sharp positive-rake carbide, rigid setups, moderate speeds and generous coolant; consider leaded C79200 if turning volume is high.
Can C77000 be welded?
Resistance and GTAW welding are workable with low heat input; oxy-fuel welding is poor due to zinc fume loss, and soldering/silver brazing are the preferred joining routes.
Can C77000 be formed, bent or molded?
Excellent cold formability in OS035/H01 with interstage anneals at 600–750 °C; hot working is limited, and cold-worked parts should be stress-relieved (~260 °C) to avoid ammonia SCC.
What surface finishes work on C77000?
Takes a bright silver-white polish and accepts nickel, chrome, silver and gold plating readily; lacquer or clear coat for long-term tarnish protection — anodizing does not apply.
C77000 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 |
|---|---|---|
| CuCu + sum of named elements ≥ 99.5% | 53.5 – 56.5 | 55 |
| NiNi includes Co | 16.5 – 19.5 | 18 |
| Pbunleaded grade | ≤ 0.05 | — |
| Fe | ≤ 0.25 | — |
| Mn | ≤ 0.5 | — |
| Znremainder, nominally ~27% | balance | — |
C77000-H02 — frequently asked
What is C77000-H02 used for?
C77000-H02 is typically used for springs, silverware base metal for plating, zippers, marine hardware and musical instrument fittings. In short: strongest unleaded nickel silver; spring and zipper grade; high-nickel, high-zinc strip.
What is the yield strength of C77000-H02?
C77000-H02 has a typical yield strength of 505 MPa (73.2 ksi) and a tensile strength of 565 MPa (81.9 ksi) — stronger than 90% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C77000-H02 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Tough and gummy (≈20% of free-cutting brass) — use sharp positive-rake carbide, rigid setups, moderate speeds and generous coolant; consider leaded C79200 if turning volume is high.
Can C77000-H02 be welded?
With care — weldability is rated fair (40/100). Resistance and GTAW welding are workable with low heat input; oxy-fuel welding is poor due to zinc fume loss, and soldering/silver brazing are the preferred joining routes.
What surface finishes work on C77000-H02?
Takes a bright silver-white polish and accepts nickel, chrome, silver and gold plating readily; lacquer or clear coat for long-term tarnish protection — anodizing does not apply.
Can C77000-H02 be formed, bent or molded?
Excellent cold formability in OS035/H01 with interstage anneals at 600–750 °C; hot working is limited, and cold-worked parts should be stress-relieved (~260 °C) to avoid ammonia SCC.
What is the maximum service temperature of C77000-H02?
C77000-H02 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C77000-H02 and C77000-OS035?
H02 is the default condition — most widely stocked strip/sheet temper: good balance of strength, formability and flatness for hardware and contacts. OS035: softest commercial condition for deep drawing, spinning and severe forming before final work-hardening. Yield strength is 505 MPa in H02 versus 186 MPa in OS035.
Sources
- CDA Alloy Datasheet C77000 (Nickel Silver 55-18) — Copper Development Association (2023)
- ASTM B122/B122M Copper-Nickel-Zinc (Nickel Silver) Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- ASTM B151/B151M Copper-Nickel-Zinc and Copper-Nickel Rod and Bar — ASTM International (2020)
- EN 12163 / EN 1652 CuNi18Zn27 (CW410J) — CEN (2016)
- 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.