Copper Alloy C74500-H06
Supply condition
UNS C74500
H06 = extra hard
For flat springs, clips and blanked parts where stiffness and yield strength dominate over formability.
Values for the H06 condition
Other C74500 tempers and conditions
C74500 is listed in 8 conditions; see the grade overview at C74500.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for deep drawing, severe bending and spinning where maximum ductility is needed. | 155 | 385 | 40 | 95 HB | 9 % IACS |
As hot rolled | Hot-rolled plate/bar stock for machined or further-worked parts where temper control is not critical. | 170 | 400 | 35 | 100 HB | — |
Quarter hard | Choose when moderate strength must be combined with substantial bending/forming ability. | 340 | 450 | 20 | 130 HB | — |
H02Default Half hard | The general-purpose stocked strip temper: good balance of strength, flatness and forming for hardware and decorative parts. | 400 | 510 | 12 | 150 HB | — |
Full hard | Use for stamped flat parts and light spring contacts needing high strength with only gentle bends. | 515 | 585 | 4 | 175 HB | — |
H06This page Extra hard | For flat springs, clips and blanked parts where stiffness and yield strength dominate over formability. | 590 | 650 | 3 | 190 HB | — |
Spring hard | Spring-temper strip for contact springs, diaphragms and snap parts; bend only with generous radii and grain-direction control. | 635 | 690 | 2 | 200 HB | — |
Extra spring hard | Maximum-strength cold-rolled strip for highly stressed flat springs; essentially no formability. | 675 | 725 | 2 | 17 HRC | 8.5 % IACS |
What is C74500-H06?
C74500-H06 is C74500 supplied in the H06 condition — for flat springs, clips and blanked parts where stiffness and yield strength dominate over formability. C74500-H06 has a yield strength of 590 MPa (85.6 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 94% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 127 GPa (18.4 Msi). C74500-H06 has a density of 8.73 g/cm³ (0.315 lb/in³), lighter than 53% of copper alloy grades. It melts at 954°C (1,749 °F). H02 is the default condition FabDigit quotes; H06 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 — 590 MPa (85.6 ksi), better than 94% of copper alloy grades
Limitations
- Limited ductility — 3%, worse than 97% of copper alloy grades
- Limited service temperature — 150°C (302 °F), 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
C74500-H06 properties
Typical room-temperature values for C74500-H06; 12 are specific to this condition. Other listed values are C74500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C74500-H06 has a density of 8.73 g/cm³ (0.315 lb/in³), lighter than 53% of copper alloy grades. It melts at 954°C (1,749 °F).
Mechanical12
C74500-H06 has a yield strength of 590 MPa (85.6 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 94% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 127 GPa (18.4 Msi).
Thermal6
C74500-H06 is rated for continuous service to 150°C (302 °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
C74500-H06 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 C74500-H06 takes about 78 MJ of energy and emits 5.2 kg of CO₂ — more than 90% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C74500-H06's machinability is poor (33/100, worse than 53% of copper alloy grades); weldability fair (40/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C74500-H06
Is C74500 easy to machine?
Machinability only ~20% of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, low feed and generous lubrication; leaded nickel silvers (C79300) are preferable for screw-machine work.
Can C74500 be welded?
Arc/gas fusion welding is poor because zinc fumes and volatilises; resistance spot/seam welding is good and silver brazing or soldering is excellent — use ventilation and low-zinc filler when fusion joining is unavoidable.
Can C74500 be formed, bent or molded?
Excellent cold formability in O61/H01 (deep drawing, spinning, coining); interanneal ~600–700 °C, and stress-relieve cold-worked parts at ~250–300 °C to avoid ammonia-related stress-corrosion cracking.
What surface finishes work on C74500?
Takes a bright white mirror polish directly and is a standard base for nickel, chrome, silver or gold plating; lacquer or clear coat outdoors to prevent slow tarnish — cannot be anodized.
C74500 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 incl. Ag | 63.5 – 66.5 | 65 |
| NiNi + Co | 9 – 11 | 10 |
| Pb | ≤ 0.1 | — |
| Fe | ≤ 0.25 | — |
| Mn | ≤ 0.5 | — |
| Znremainder, ~25% | balance | — |
C74500-H06 — frequently asked
What is C74500-H06 used for?
C74500-H06 is typically used for zippers, eyeglass frames, hardware, electrical connectors and nameplates. In short: classic 65-10 nickel silver; bright white plating base; not for screw machining.
What is the yield strength of C74500-H06?
C74500-H06 has a typical yield strength of 590 MPa (85.6 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 94% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C74500-H06 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 53% of copper alloy grades). Machinability only ~20% of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, low feed and generous lubrication; leaded nickel silvers (C79300) are preferable for screw-machine work.
Can C74500-H06 be welded?
With care — weldability is rated fair (40/100). Arc/gas fusion welding is poor because zinc fumes and volatilises; resistance spot/seam welding is good and silver brazing or soldering is excellent — use ventilation and low-zinc filler when fusion joining is unavoidable.
What surface finishes work on C74500-H06?
Takes a bright white mirror polish directly and is a standard base for nickel, chrome, silver or gold plating; lacquer or clear coat outdoors to prevent slow tarnish — cannot be anodized.
Can C74500-H06 be formed, bent or molded?
Excellent cold formability in O61/H01 (deep drawing, spinning, coining); interanneal ~600–700 °C, and stress-relieve cold-worked parts at ~250–300 °C to avoid ammonia-related stress-corrosion cracking.
What is the maximum service temperature of C74500-H06?
C74500-H06 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C74500-H02 and C74500-H10?
H02 is the default condition — the general-purpose stocked strip temper: good balance of strength, flatness and forming for hardware and decorative parts. H10: maximum-strength cold-rolled strip for highly stressed flat springs; essentially no formability. Yield strength is 400 MPa in H02 versus 675 MPa in H10.
Sources
- 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 (2021)
- CDA Alloy Database — C74500 property sheet — 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.