Copper Alloy C74400-H04
Supply condition
UNS C74400
H04 = full hard
Hard temper for flat springs, contacts and parts needing stiffness with only gentle bends.
Values for the H04 condition
Other C74400 tempers and conditions
C74400 is listed in 10 conditions; see the grade overview at C74400.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.050 mm grain size | Softest strip temper for deep drawing and severe forming. | 125 | 365 | 45 | 68 HB | 11 % IACS |
Annealed to 0.035 mm grain size | General-purpose annealed strip balancing drawability and surface finish. | 140 | 385 | 40 | 76 HB | 11 % IACS |
Annealed to 0.015 mm grain size | Fine-grain anneal for smooth 'orange-peel-free' surfaces on shallow-formed decorative parts. | 165 | 405 | 35 | 86 HB | 10.5 % IACS |
Quarter hard | Light temper when moderate bending is still required after rolling. | 340 | 450 | 20 | 107 HB | 10 % IACS |
H02Default Half hard | The default stocked strip/rod temper — good springback control with useful residual formability. | 440 | 515 | 12 | 138 HB | 9.8 % IACS |
Three-quarter hard | Intermediate temper for flat stampings needing higher yield than half hard. | 500 | 565 | 8 | 155 HB | 9.7 % IACS |
H04This page Full hard | Hard temper for flat springs, contacts and parts needing stiffness with only gentle bends. | 545 | 620 | 4 | 170 HB | 9.6 % IACS |
Extra hard | Extra-hard strip for high-stiffness clips and flat spring blanks with minimal forming. | 590 | 675 | 3 | 180 HB | 9.5 % IACS |
Spring hard | Spring temper strip/wire for resilient contacts and springs. | 630 | 725 | 2 | 13 HRC | 9.5 % IACS |
Extra spring hard | Maximum cold-worked strength for thin spring stock; essentially no forming capability. | 665 | 760 | 2 | 15 HRC | 9.4 % IACS |
What is C74400-H04?
C74400-H04 is C74400 supplied in the H04 condition — hard temper for flat springs, contacts and parts needing stiffness with only gentle bends. C74400-H04 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 92% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 124 GPa (18 Msi). C74400-H04 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 1,020°C (1,868 °F). H02 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 90/100, better than 99% of copper alloy grades
- High strength — 545 MPa (79 ksi), better than 92% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- High embodied carbon — 4.5 kg CO₂/kg, worse than 79% of copper alloy grades
- Poor heat conductor — 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades
- Low electrical conductivity — 9.6 % IACS, worse than 76% of copper alloy grades
C74400-H04 properties
Typical room-temperature values for C74400-H04; 18 are specific to this condition. Other listed values are C74400 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C74400-H04 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 1,020°C (1,868 °F).
Mechanical12
C74400-H04 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 92% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C74400-H04 is rated for continuous service to 190°C (374 °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
C74400-H04 conducts electricity at 9.6 % IACS, worse than 76% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C74400-H04 takes about 62 MJ of energy and emits 4.5 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 35%.
Manufacturability7
C74400-H04's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability fair (48/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C74400-H04
Is C74400 easy to machine?
Rating ~20 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, moderate speed and generous coolant, or specify a leaded nickel silver if heavy machining is needed.
Can C74400 be welded?
Best joined by silver brazing or soft soldering; resistance and GTAW welding are possible with care but zinc fuming and hot cracking must be controlled — no cast-alloy fusion practice.
Can C74400 be formed, bent or molded?
Excellent cold formability in annealed tempers (deep draw, roll form, coin); interstage anneal at 600–750 °C and stress-relieve cold-worked parts near 260 °C to avoid ammonia-induced SCC.
What surface finishes work on C74400?
Buffs to a bright silver-white finish and takes nickel, chrome, silver or gold plating readily; commonly lacquered or chemically blackened for decorative hardware.
C74400 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 |
|---|---|---|
| Cusilver-white nickel silver base | 63 – 66.5 | 65 |
| NiNi + Co | 7 – 9 | 8 |
| Pb | ≤ 0.1 | — |
| Fe | ≤ 0.25 | — |
| Mn | ≤ 0.5 | — |
| Znremainder, ~27 % | balance | — |
C74400-H04 — frequently asked
What is C74400-H04 used for?
C74400-H04 is typically used for costume jewelry, hardware trim, nameplates and decorative fittings. In short: low-cost nickel silver; bright silvery stamping strip; cheaper than 65-10.
What is the yield strength of C74400-H04?
C74400-H04 has a typical yield strength of 545 MPa (79 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 92% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C74400-H04 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Rating ~20 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, moderate speed and generous coolant, or specify a leaded nickel silver if heavy machining is needed.
Can C74400-H04 be welded?
With care — weldability is rated fair (48/100). Best joined by silver brazing or soft soldering; resistance and GTAW welding are possible with care but zinc fuming and hot cracking must be controlled — no cast-alloy fusion practice.
What surface finishes work on C74400-H04?
Buffs to a bright silver-white finish and takes nickel, chrome, silver or gold plating readily; commonly lacquered or chemically blackened for decorative hardware.
Can C74400-H04 be formed, bent or molded?
Excellent cold formability in annealed tempers (deep draw, roll form, coin); interstage anneal at 600–750 °C and stress-relieve cold-worked parts near 260 °C to avoid ammonia-induced SCC.
What is the maximum service temperature of C74400-H04?
C74400-H04 is rated for continuous use to about 190°C (374 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C74400-H02 and C74400-OS050?
H02 is the default condition — the default stocked strip/rod temper — good springback control with useful residual formability. OS050: softest strip temper for deep drawing and severe forming. Yield strength is 440 MPa in H02 versus 125 MPa in OS050.
Sources
- ASTM B122/B122M — Copper-Nickel-Zinc (Nickel Silver) Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- ASTM B151/B151M — Copper-Nickel-Zinc Alloy Rod and Bar — ASTM International (2021)
- CDA Standard Designation and Alloy Data (C74000 series nickel silvers) — 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.