Copper Alloy C74000-H04
Supply condition
UNS C74000
H04 = full hard
Pick for flat springs, contacts and stamped parts needing high strength with only gentle bends.
Values for the H04 condition
Other C74000 tempers and conditions
C74000 is listed in 8 conditions; see the grade overview at C74000.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Pick for deep drawing, spinning and severe bending of decorative parts. | 120 | 345 | 45 | 75 HB | — |
As hot rolled | Pick for heavier hot-rolled plate/bar stock where a soft, machinable, weldable condition is enough. | 140 | 360 | 40 | 85 HB | — |
Quarter hard | Pick when moderate stiffness is needed but the part still requires appreciable bending or forming. | 275 | 415 | 25 | 120 HB | — |
Light drawn | Pick for drawn rod, wire or tube needing straightness and moderate strength with some upsetting ability. | 330 | 450 | 18 | 132 HB | 9 % IACS |
H02Default Half hard | Default stocked strip/sheet temper — best all-round balance of strength, bendability and polished appearance. | 380 | 470 | 12 | 145 HB | — |
H04This page Full hard | Pick for flat springs, contacts and stamped parts needing high strength with only gentle bends. | 490 | 550 | 4 | 175 HB | — |
Extra hard | Pick for maximum stiffness and spring-back in flat springs and clips where forming is minimal. | 550 | 620 | 2.5 | 195 HB | — |
Spring hard | Pick for high-load flat springs and contact fingers where practically no forming is required. | 610 | 670 | 2 | 14 HRC | 8.5 % IACS |
What is C74000-H04?
C74000-H04 is C74000 supplied in the H04 condition — pick for flat springs, contacts and stamped parts needing high strength with only gentle bends. C74000-H04 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 125 GPa (18.1 Msi). C74000-H04 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,010°C (1,850 °F). H02 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 88/100, better than 97% of copper alloy grades
- High strength — 490 MPa (71.1 ksi), better than 88% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- High embodied carbon — 5.2 kg CO₂/kg, worse than 88% of copper alloy grades
- Low electrical conductivity — 9 % IACS, worse than 78% of copper alloy grades
- Poor heat conductor — 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades
C74000-H04 properties
Typical room-temperature values for C74000-H04; 11 are specific to this condition. Other listed values are C74000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C74000-H04 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,010°C (1,850 °F).
Mechanical12
C74000-H04 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
C74000-H04 is rated for continuous service to 180°C (356 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C74000-H04 conducts electricity at 9 % IACS, worse than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C74000-H04 takes about 75 MJ of energy and emits 5.2 kg of CO₂ — more than 88% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C74000-H04's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability good (55/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C74000-H04
Is C74000 easy to machine?
Gummy and abrasive on tooling (≈20 % of free-cutting brass) — use sharp positive-rake carbide, high speed with light feeds and copious lubricant; consider leaded C79300 if turning volume is high.
Can C74000 be welded?
Best joined by GTAW/GMAW with Cu-Ni filler or by silver brazing/soldering; resistance welding is fair and oxyacetylene welding risks zinc fume loss — ventilate and avoid overheating.
Can C74000 be formed, bent or molded?
Annealed and quarter-hard stock deep-draws and coins very well; interstage anneal at 600–750 °C and stress-relieve hard tempers (~230–260 °C) to avoid ammonia-driven stress-corrosion cracking.
What surface finishes work on C74000?
Takes a bright mirror polish and is an excellent base for Ag, Ni or Cr plating; lacquer or clear coat if tarnish-free service in humid or handled applications is required.
C74000 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 |
|---|---|---|
| Cuincluding Ag per ASTM practice | 69 – 73.5 | 71 |
| Niincluding Co | 9 – 11 | 10 |
| Pb | ≤ 0.1 | — |
| Fe | ≤ 0.25 | — |
| Mn | ≤ 0.5 | — |
| Znremainder, nominally ~19 % | balance | — |
C74000-H04 — frequently asked
What is C74000-H04 used for?
C74000-H04 is typically used for hardware fittings, eyeglass frames, musical instruments and decorative trim. In short: most formable nickel silver; excellent plating substrate; hardest common nickel silver.
What is the yield strength of C74000-H04?
C74000-H04 has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C74000-H04 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Gummy and abrasive on tooling (≈20 % of free-cutting brass) — use sharp positive-rake carbide, high speed with light feeds and copious lubricant; consider leaded C79300 if turning volume is high.
Can C74000-H04 be welded?
Yes — weldability is rated good (55/100). Best joined by GTAW/GMAW with Cu-Ni filler or by silver brazing/soldering; resistance welding is fair and oxyacetylene welding risks zinc fume loss — ventilate and avoid overheating.
What surface finishes work on C74000-H04?
Takes a bright mirror polish and is an excellent base for Ag, Ni or Cr plating; lacquer or clear coat if tarnish-free service in humid or handled applications is required.
Can C74000-H04 be formed, bent or molded?
Annealed and quarter-hard stock deep-draws and coins very well; interstage anneal at 600–750 °C and stress-relieve hard tempers (~230–260 °C) to avoid ammonia-driven stress-corrosion cracking.
What is the maximum service temperature of C74000-H04?
C74000-H04 is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C74000-H02 and C74000-O60?
H02 is the default condition — default stocked strip/sheet temper — best all-round balance of strength, bendability and polished appearance. O60: pick for deep drawing, spinning and severe bending of decorative parts. Yield strength is 380 MPa in H02 versus 120 MPa in O60.
Sources
- ASTM B122/B122M — Copper-Nickel-Tin, Copper-Nickel-Zinc (Nickel Silver) Plate, Sheet, Strip and Rolled Bar — ASTM International (2021)
- ASTM B151/B151M — Copper-Nickel-Zinc and Copper-Nickel Rod and Bar — ASTM International (2021)
- CDA/UNS C74000 alloy datasheet (copper.org Alloy Database) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Nickel Silvers) — 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.