Copper Alloy C78200
UNS C78200
C78200 is a leaded version of 65-10 nickel silver (Cu-Ni-Zn plus lead) in which the lead phase breaks chips for precision turning; it is stocked in OS035 and OS015 annealed tempers and H01 through H06.
Reference datasheet — C78200 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
C78200 tempers and conditions
C78200 is supplied in 7 conditions, soft to hard. H02 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.035 mm grain size | Pick this fully annealed 0.035 mm average grain size temper for deep drawing, curling and other severe cold forming, accepting the lowest strength (152 MPa yield) of the range. | 152 | 372 | 40 | 80 HB | — |
Annealed to 0.015 mm grain size | Choose the fine 0.015 mm grain annealed temper when formed surfaces must stay smooth with little orange peel, for shallow draws and precision blanks that are later polished. | 172 | 400 | 35 | 95 HB | — |
Quarter hard | Pick quarter hard (≈11 % cold reduction) as the transition temper when parts still need bending but require 331 MPa yield; formability is below annealed stock. | 331 | 434 | 20 | 120 HB | — |
H02Default Half hard | Choose half hard (≈21 % cold reduction), the most commonly stocked temper, for precision turning and stamping: 407 MPa yield, good chip breaking and moderate bending at 10 % elongation. | 407 | 483 | 10 | 140 HB | — |
Three-quarter hard | Pick three-quarter hard (≈29 % cold reduction) for spring contacts and stiff thin sections that still take small-radius bends; elongation drops to 6 % at 462 MPa yield. | 462 | 524 | 6 | 158 HB | — |
Full hard | Use full hard (≈37 % cold reduction) for bar and strip needing 496 MPa yield and the best machined surface finish; bends must use a large radius and run with the grain (3 % elongation). | 496 | 565 | 3 | 170 HB | — |
Extra hard | Choose extra hard (≈50 % cold reduction) for thin springs, washers and parts that are not formed further, giving 545 MPa yield and 620 MPa tensile at only 2 % elongation. | 545 | 620 | 2 | 185 HB | — |
What is C78200?
C78200 is a leaded version of 65-10 nickel silver (Cu-Ni-Zn plus lead) in which the lead phase breaks chips for precision turning; it is stocked in OS035 and OS015 annealed tempers and H01 through H06. Engineers use it for turned and stamped nickel silver parts that must keep a silver-white surface, with default values of 407 MPa yield, 483 MPa tensile, 10% elongation, 140 HB and 76 HRB. Machinability is about 60% of free-cutting brass (score 62), but lead rules out fusion welding and hot working, service is limited to roughly 150 °C, and cold formability is modest (score 45). Choose unleaded C77400 where deep drawing dominates. C78200 has a density of 8.72 g/cm³ (0.315 lb/in³), lighter than 54% of copper alloy grades. It melts at 966°C (1,771 °F). C78200 has a yield strength of 407 MPa (59 ksi) and a tensile strength of 483 MPa (70.1 ksi) — stronger than 81% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 128 GPa (18.6 Msi).
What is C78200 used for?
- screw-machine parts
- plumbing fittings
- eyeglass frame components
- hardware
Advantages
- High strength — 407 MPa (59 ksi), better than 81% of copper alloy grades
- Easy to machine — 62/100, better than 75% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- High embodied carbon — 5 kg CO₂/kg, worse than 86% of copper alloy grades
- Poor heat conductor — 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades
- Low electrical conductivity — 9 % IACS, worse than 78% of copper alloy grades
C78200 properties
Typical room-temperature values for C78200-H02; bars are the position among copper alloy grades.
Physical3
C78200 has a density of 8.72 g/cm³ (0.315 lb/in³), lighter than 54% of copper alloy grades. It melts at 966°C (1,771 °F).
Mechanical12
C78200 has a yield strength of 407 MPa (59 ksi) and a tensile strength of 483 MPa (70.1 ksi) — stronger than 81% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 128 GPa (18.6 Msi).
Thermal6
C78200 is rated for continuous service to 150°C (302 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades. Thermal expansion is 16.7 µm/m·K (9.28 µin/in·°F).
Electrical3
C78200 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 C78200 takes about 72 MJ of energy and emits 5 kg of CO₂ — more than 86% of copper alloy grades. Typical recycled content is 40%.
Manufacturability6
C78200's machinability is good (62/100, better than 75% of copper alloy grades); weldability poor (20/100); formability fair (45/100).
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. C78200 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C78200
Is C78200 easy to machine?
Lead gives good chip breaking, with a machinability rating around 60% of free-cutting brass. Use sharp positive-rake tools at medium-to-high speed with emulsion coolant for stable threading and small turned features.
Can C78200 be welded?
Fusion welding is not recommended — lead causes hot cracking and porosity. Use soft solder (Sn-Ag or Sn-Pb) or low-temperature silver brazing, and keep brazing temperature as low as practical.
Can C78200 be formed, bent or molded?
The soft tempers (OS015/OS035) deep draw and bend well, but cold formability drops sharply above H02, so bend with the grain and increase bend radii. Interanneal at 600–750 °C to remove work hardening; hot working is poor, so avoid hot forging and hot rolling.
C78200 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 |
|---|---|---|
| Cu | 63 – 67 | 65 |
| NiNi+Co | 7 – 9 | 8 |
| Pbadded for free machining | 1.5 – 2.5 | 2 |
| Fe | ≤ 0.35 | |
| Mn | ≤ 0.5 | |
| Znbalance, about 25% | balance |
What surface finishes work on C78200?
The silver-white surface polishes to a high gloss on its own and accepts nickel, chrome and silver plating, usually with clear lacquer after polishing. Anodizing does not apply; chemical polishing or passivation after lead removal helps resist tarnish.
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 C78200 cost?
C78200 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.
C78200 — frequently asked
What is C78200 used for?
C78200 is typically used for screw-machine parts, plumbing fittings, eyeglass frame components and hardware. In short: leaded 65-10 nickel silver; turns at 60% of brass; silver-white without plating.
What is the yield strength of C78200?
C78200 has a typical yield strength of 407 MPa (59 ksi) and a tensile strength of 483 MPa (70.1 ksi) — stronger than 81% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C78200 easy to machine?
Reasonably — machinability is rated good (62/100, better than 75% of copper alloy grades). Lead gives good chip breaking, with a machinability rating around 60% of free-cutting brass. Use sharp positive-rake tools at medium-to-high speed with emulsion coolant for stable threading and small turned features.
Can C78200 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is not recommended — lead causes hot cracking and porosity. Use soft solder (Sn-Ag or Sn-Pb) or low-temperature silver brazing, and keep brazing temperature as low as practical.
What surface finishes work on C78200?
The silver-white surface polishes to a high gloss on its own and accepts nickel, chrome and silver plating, usually with clear lacquer after polishing. Anodizing does not apply; chemical polishing or passivation after lead removal helps resist tarnish.
Can C78200 be formed, bent or molded?
The soft tempers (OS015/OS035) deep draw and bend well, but cold formability drops sharply above H02, so bend with the grain and increase bend radii. Interanneal at 600–750 °C to remove work hardening; hot working is poor, so avoid hot forging and hot rolling.
What is the maximum service temperature of C78200?
C78200 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 C78200-H02 and C78200-OS035?
H02 is the default condition — choose half hard (≈21 % cold reduction), the most commonly stocked temper, for precision turning and stamping: 407 MPa yield, good chip breaking and moderate bending at 10 % elongation. OS035: pick this fully annealed 0.035 mm average grain size temper for deep drawing, curling and other severe cold forming, accepting the lowest strength (152 MPa yield) of the range. Yield strength is 407 MPa in H02 versus 152 MPa in OS035.
How much does C78200 cost?
C78200 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
- Copper Alloy C78200 (Leaded Nickel Silver 65-8-2) datasheet — Copper Development Association (copper.org) (2023)
- ASTM B122/B122M — Copper-Nickel-Tin/Copper-Nickel-Zinc Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- ASTM B151/B151M — Copper-Nickel-Zinc (Nickel Silver) and Copper-Nickel Rod and Bar — ASTM International (2019)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — 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.