Copper Alloy C74400
UNS C74400
C74400 is a low-nickel copper-nickel-zinc (nickel silver) wrought alloy supplied as strip and sheet from OS050, OS035 and OS015 annealed conditions through H01–H10 rolled tempers.
Reference datasheet — C74400 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
C74400 tempers and conditions
C74400 is supplied in 10 conditions, soft to hard. H02 is the default FabDigit quotes; the values on this page are for it.
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 |
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?
C74400 is a low-nickel copper-nickel-zinc (nickel silver) wrought alloy supplied as strip and sheet from OS050, OS035 and OS015 annealed conditions through H01–H10 rolled tempers. It gives a bright silvery appearance at lower cost than 65-10 nickel silver and reaches 515 MPa tensile strength, 440 MPa yield and 75 HRB with 12% elongation, suiting stampings and decorative hardware. Formability rating is 70, service is limited to 200 °C, arc welding is difficult because zinc volatilises, and cold-worked parts need stress relief against ammonia SCC. C74500 is the alternative when a whiter colour is required. C74400 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). C74400 has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 124 GPa (18 Msi).
What is C74400 used for?
- costume jewelry
- hardware trim
- nameplates
- decorative fittings
Advantages
- Polishes to a fine finish — 90/100, better than 99% of copper alloy grades
- High strength — 440 MPa (63.8 ksi), better than 85% of copper alloy grades
- Forms and bends easily — 70/100, better than 80% of copper alloy grades
Limitations
- Difficult to machine — 25/100, worse than 86% 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 — 9.8 % IACS, worse than 76% of copper alloy grades
C74400 properties
Typical room-temperature values for C74400-H02; bars are the position among copper alloy grades.
Physical3
C74400 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 has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C74400 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
C74400 conducts electricity at 9.8 % IACS, worse than 76% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C74400 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's machinability is poor (25/100, worse than 86% of copper alloy grades); weldability fair (52/100); formability very good (70/100).
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. C74400 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C74400
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.
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 |
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.
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 C74400 cost?
C74400 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.
C74400 — frequently asked
What is C74400 used for?
C74400 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?
C74400 has a typical yield strength of 440 MPa (63.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 85% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C74400 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 86% 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 be welded?
With care — weldability is rated fair (52/100). 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?
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 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?
C74400 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 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.
How much does C74400 cost?
C74400 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-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; 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.