Copper Alloy C77300
UNS C77300
C77300 is a copper-zinc-nickel (nickel silver) braze-welding filler that pairs higher deposit strength with a silvery colour match to nickel-silver base metals.
Reference datasheet — C77300 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 AW condition
C77300 tempers and conditions
C77300 is supplied in one standard condition, AW. AW is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways C77300 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FC | Flux-Coated Rod | Supply form |
ROD-ASDRAWN | As-Drawn Rod | Supply form |
WIRE | Spooled Wire | Supply form |
What is C77300?
C77300 is a copper-zinc-nickel (nickel silver) braze-welding filler that pairs higher deposit strength with a silvery colour match to nickel-silver base metals. Deposits run about 275 MPa yield, 480 MPa tensile, 12% elongation and 130 HB, and tolerate service to 300 °C — the highest in this filler group. Forms on file include bare rod, flux-coated rod, wire and as-drawn rod for braze welding steel, nickel silver and decorative assemblies. Elongation is lower than the brass fillers and zinc fuming at the 950–1000 °C flame temperature requires extraction; use C68100 where a brass-gold colour is acceptable. C77300 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 921°C (1,690 °F). C77300 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
What is C77300 used for?
- nickel-silver fabrication
- high-strength steel braze welding
- decorative/architectural metalwork
- musical instrument repair
Advantages
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
Limitations
- Low electrical conductivity — 7 % IACS, 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
C77300 properties
Typical room-temperature values for C77300-AW; bars are the position among copper alloy grades.
Physical3
C77300 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 921°C (1,690 °F).
Mechanical9
C77300 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
Thermal6
C77300 is rated for continuous service to 300°C (572 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades. Thermal expansion is 19.5 µm/m·K (10.8 µin/in·°F).
Electrical3
C77300 conducts electricity at 7 % IACS, worse than 86% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C77300 takes about 70 MJ of energy and emits 4.5 kg of CO₂ — more than 84% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C77300's machinability is fair (40/100, better than 57% of copper alloy grades); weldability good (55/100); formability fair (50/100).
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. C77300 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C77300
Is C77300 easy to machine?
Braze-weld deposits machine like a tough nickel silver — use sharp carbide, positive rake and moderate speeds; expect gummy chips and roughly one third of free-cutting brass productivity.
Can C77300 be welded?
Braze weld at ~950–1000 °C flame temperature with a slightly oxidizing flame and borax-type brass flux; keep the base metal below its melting point, avoid overheating to limit zinc fuming, and provide fume extraction.
Can C77300 be formed, bent or molded?
Rod can be hand-bent for hard-to-reach joints but work-hardens quickly; stress-relieve or anneal drawn rod before tight bends.
C77300 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 |
|---|---|---|
| CuAWS A5.8 RBCuZn-D | 46 – 50 | 48 |
| Nigives silvery color and strength | 9 – 11 | 10 |
| Sisuppresses zinc fuming/oxidation | 0.04 – 0.25 | 0.12 |
| Pdeoxidizer | ≤ 0.25 | 0.1 |
| Fe | ≤ 0.25 | |
| Sn | ≤ 0.25 | |
| Mn | ≤ 0.25 | |
| Al | ≤ 0.01 | |
| Pb | ≤ 0.05 | |
| Other, total | ≤ 0.5 | |
| Znremainder, nominally ~42 % | balance |
What surface finishes work on C77300?
Deposit polishes to a silvery finish that blends with nickel silver base metal; remove flux residue with hot water/pickle, and nickel- or chrome-plate if a decorative match to steel is needed (no anodizing).
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 C77300 cost?
C77300 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C77300 — frequently asked
What is C77300 used for?
C77300 is typically used for nickel-silver fabrication, high-strength steel braze welding, decorative/architectural metalwork and musical instrument repair. In short: silvery colour-matched deposit; highest service temperature here; strong braze-weld filler.
What is the yield strength of C77300?
C77300 has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 57% of copper alloy grades.
Is C77300 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Braze-weld deposits machine like a tough nickel silver — use sharp carbide, positive rake and moderate speeds; expect gummy chips and roughly one third of free-cutting brass productivity.
Can C77300 be welded?
Yes — weldability is rated good (55/100). Braze weld at ~950–1000 °C flame temperature with a slightly oxidizing flame and borax-type brass flux; keep the base metal below its melting point, avoid overheating to limit zinc fuming, and provide fume extraction.
What surface finishes work on C77300?
Deposit polishes to a silvery finish that blends with nickel silver base metal; remove flux residue with hot water/pickle, and nickel- or chrome-plate if a decorative match to steel is needed (no anodizing).
Can C77300 be formed, bent or molded?
Rod can be hand-bent for hard-to-reach joints but work-hardens quickly; stress-relieve or anneal drawn rod before tight bends.
What is the maximum service temperature of C77300?
C77300 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does C77300 cost?
C77300 is a high-cost copper alloy ($$$$), 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
- AWS A5.8/A5.8M — Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- AWS A5.7/A5.7M — Specification for Copper and Copper-Alloy Bare Welding Rods and Electrodes — American Welding Society (2021)
- UNS C77300 alloy record (nickel silver braze filler) — Copper Development Association / copper.org (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (nickel silvers) — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (braze welding of steel and cast iron) — ASM International (1993)
- Nickel silver braze welding rod (RBCuZn-D) datasheets — Harris Products Group / Lucas-Milhaupt (2022)
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.