Copper Alloy C74000
UNS C74000
C74000 is a general-purpose wrought nickel silver (Cu-Ni-Zn) in the C70000–C79999 group, supplied in O60, M20, H01–H08 and H55 tempers.
Reference datasheet — C74000 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the H02 condition
C74000 tempers and conditions
C74000 is supplied in 8 conditions, soft to hard. H02 is the default FabDigit quotes; the values on this page are for it.
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 | — |
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?
C74000 is a general-purpose wrought nickel silver (Cu-Ni-Zn) in the C70000–C79999 group, supplied in O60, M20, H01–H08 and H55 tempers. It balances formability (rated 60) with corrosion resistance and a bright silvery colour, and in the default temper delivers 380 MPa yield, 470 MPa tensile, 12% elongation and 145 HB (75 HRB) with service to 200 °C. The non-leaded chemistry machines poorly and hard tempers can suffer ammonia stress-corrosion cracking; consider C73500 for higher strength or leaded C79300 where machining dominates. C74000 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). C74000 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 125 GPa (18.1 Msi).
What is C74000 used for?
- hardware fittings
- eyeglass frames
- musical instruments
- decorative trim
Advantages
- Polishes to a fine finish — 88/100, better than 97% of copper alloy grades
- High strength — 380 MPa (55.1 ksi), better than 77% of copper alloy grades
Limitations
- 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 properties
Typical room-temperature values for C74000-H02; bars are the position among copper alloy grades.
Physical3
C74000 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 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
C74000 is rated for continuous service to 200°C (392 °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 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 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's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability good (55/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C74000 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C74000
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.
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 |
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.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
How much does C74000 cost?
C74000 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C74000 — frequently asked
What is C74000 used for?
C74000 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?
C74000 has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C74000 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 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?
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 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?
C74000 is rated for continuous use to about 200°C (392 °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.
How much does C74000 cost?
C74000 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.