Copper Alloy C77100
UNS C77100
C77100 is a high-nickel wrought nickel silver (Cu-Ni-Zn) from the C70000–C79999 family, strengthened by cold work rather than heat treatment and stocked in O60, H01, H02, H04, H06, H08, H10 and HR50 tempers as strip, sheet, wire and rod.
Reference datasheet — C77100 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 O60 condition
C77100 tempers and conditions
C77100 is supplied in 8 conditions, soft to hard. O60 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 |
|---|---|---|---|---|---|---|
O60Default Soft annealed | Default stock condition for deep drawing, bending and stamping of blanks before final forming. | 180 | 420 | 40 | 55 HRB | — |
Quarter hard | Light temper when moderate stiffness must be combined with continued bending/forming. | 380 | 500 | 25 | 130 HB | 4.5 % IACS |
Half hard | General-purpose semi-rigid temper for machined and lightly formed precision parts. | 470 | 570 | 15 | 155 HB | 4.5 % IACS |
Cold worked and stress-relieved | Use when cold-worked strength is required but residual-stress SCC (ammonia atmospheres) must be avoided. | 500 | 580 | 14 | 7 HRC | 4.5 % IACS |
Full hard | Choose for flat springs, contacts and wear surfaces where only gentle forming is needed. | 570 | 660 | 6 | 10 HRC | 4.4 % IACS |
Extra hard | Higher-strength strip for stamped contacts and stiff clips with minimal bending. | 640 | 720 | 4 | 13 HRC | 4.4 % IACS |
Spring hard | Spring strip for flexures and diaphragms needing high elastic limit and white finish. | 700 | 790 | 3 | 16 HRC | 4.4 % IACS |
Extra spring hard | Maximum-strength cold-rolled temper for thin, highly stressed spring elements. | 760 | 840 | 2 | 18 HRC | 4.4 % IACS |
What is C77100?
C77100 is a high-nickel wrought nickel silver (Cu-Ni-Zn) from the C70000–C79999 family, strengthened by cold work rather than heat treatment and stocked in O60, H01, H02, H04, H06, H08, H10 and HR50 tempers as strip, sheet, wire and rod. Engineers specify it for its bright white colour, dimensional stability and extra corrosion resistance in precision components; the default condition gives 180 MPa yield, 420 MPa tensile, 40% elongation and 55 HRB with a formability score of 85. Service is limited to about 250 °C, and machinability is only around 20% of free-cutting brass, so leaded C78200 or C79200 is the better choice for high-volume screw-machine work. C77100 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 1,040°C (1,904 °F). C77100 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 59% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 132 GPa (19.1 Msi).
What is C77100 used for?
- precision instrument parts
- optical hardware
- high-end fittings
Advantages
- Polishes to a fine finish — 88/100, better than 97% of copper alloy grades
- Stiff — 132 GPa (19.1 Msi), better than 93% of copper alloy grades
- Forms and bends easily — 85/100, better than 85% of copper alloy grades
- Ductile — tolerates forming and impact — 40%, better than 84% of copper alloy grades
Limitations
- Poor heat conductor — 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 99% of copper alloy grades
- Low electrical conductivity — 4.6 % IACS, worse than 96% of copper alloy grades
- High embodied carbon — 5.8 kg CO₂/kg, worse than 91% of copper alloy grades
C77100 properties
Typical room-temperature values for C77100-O60; bars are the position among copper alloy grades.
Physical3
C77100 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 1,040°C (1,904 °F).
Mechanical11
C77100 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 59% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 132 GPa (19.1 Msi).
Thermal6
C77100 is rated for continuous service to 250°C (482 °F). It conducts heat at 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 99% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C77100 conducts electricity at 4.6 % IACS, worse than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (63/100), better than 52% of copper alloy grades.
Sustainability4
Producing a kilogram of C77100 takes about 78 MJ of energy and emits 5.8 kg of CO₂ — more than 90% of copper alloy grades. Typical recycled content is 35%.
Manufacturability6
C77100's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability good (55/100); formability excellent (85/100).
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. C77100 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C77100
Is C77100 easy to machine?
Tough and gummy — use sharp, positive-rake carbide or HSS-Co tools, moderate speed with heavy feed and good coolant; rating only ~20 % of free-cutting brass, so specify a leaded nickel silver if screw-machining volumes are high.
Can C77100 be welded?
Best joined by resistance welding, GTAW with matched or Cu-Ni filler, or silver brazing; avoid overheating to limit zinc fuming and keep parts stress-relieved to prevent cracking.
Can C77100 be formed, bent or molded?
Excellent deep-draw and stamping performance in the annealed temper, but it work-hardens fast — plan interanneals around 600–750 °C with rapid cooling.
C77100 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 |
|---|---|---|
| Nihigh-nickel grade; verify against mill certificate — C77100 limits are less widely published than C77000 | 23 – 27 | 25 |
| Cu | 46 – 50 | 48 |
| Mndeoxidiser | ≤ 0.5 | 0.2 |
| Fe | ≤ 0.25 | |
| Pb | ≤ 0.05 | |
| Znremainder, nominally ~27 % | balance |
What surface finishes work on C77100?
Polishes to a bright white, tarnish-resistant surface; readily nickel-, chrome- or silver-plated, and lacquering is used to preserve the as-polished lustre.
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 C77100 cost?
C77100 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.
C77100 — frequently asked
What is C77100 used for?
C77100 is typically used for precision instrument parts, optical hardware and high-end fittings. In short: highest-nickel nickel silver; bright white, tarnish resistant; deep-draw formability score 85.
What is the yield strength of C77100?
C77100 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 59% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C77100 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Tough and gummy — use sharp, positive-rake carbide or HSS-Co tools, moderate speed with heavy feed and good coolant; rating only ~20 % of free-cutting brass, so specify a leaded nickel silver if screw-machining volumes are high.
Can C77100 be welded?
Yes — weldability is rated good (55/100). Best joined by resistance welding, GTAW with matched or Cu-Ni filler, or silver brazing; avoid overheating to limit zinc fuming and keep parts stress-relieved to prevent cracking.
What surface finishes work on C77100?
Polishes to a bright white, tarnish-resistant surface; readily nickel-, chrome- or silver-plated, and lacquering is used to preserve the as-polished lustre.
Can C77100 be formed, bent or molded?
Excellent deep-draw and stamping performance in the annealed temper, but it work-hardens fast — plan interanneals around 600–750 °C with rapid cooling.
What is the maximum service temperature of C77100?
C77100 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C77100-O60 and C77100-H10?
O60 is the default condition — default stock condition for deep drawing, bending and stamping of blanks before final forming. H10: maximum-strength cold-rolled temper for thin, highly stressed spring elements. Yield strength is 180 MPa in O60 versus 760 MPa in H10.
How much does C77100 cost?
C77100 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
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- CDA/UNS Copper Alloy Data (C77000-series nickel silvers) — Copper Development Association (2023)
- ASTM B122/B122M — Copper-Nickel-Zinc (Nickel Silver) Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- GB/T 2059 / GB/T 2040 — SAC (2017)
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.