Copper Alloy C10500
UNS C10500
C10500 is a higher-silver variant of oxygen-free copper, specified where conductors must resist softening at elevated temperature.
Reference datasheet — C10500 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 H04 condition
C10500 tempers and conditions
C10500 is supplied in 12 conditions, soft to hard. H04 is the default FabDigit quotes; the values on this page are for it.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As hot extruded | Extruded rod, tube and profile in the as-pressed state, typically drawn or annealed afterwards. | 62 | 221 | 50 | 42 HB | 100 % IACS |
Annealed to 0.050 mm grain size | Softest stock condition — pick for deep drawing, spinning, tight bends and maximum conductivity. | 69 | 221 | 45 | 45 HB | 101 % IACS |
As hot rolled | Mill condition for hot-rolled plate and busbar where forming and conductivity matter more than strength. | 69 | 228 | 45 | 45 HB | 100 % IACS |
Hot rolled and annealed | Fine-grain annealed plate/bar for a smoother formed surface than coarse-grain OS050. | 76 | 234 | 45 | 48 HB | 101 % IACS |
1/8 hard | Minimal cold work for flatness and handling stiffness while keeping most of the annealed ductility. | 170 | 250 | 30 | 52 HB | 100 % IACS |
Light drawn | Lightly drawn tube/rod: straight and dimensionally accurate but still bendable for coils and fittings. | 195 | 255 | 25 | 60 HB | 100 % IACS |
Quarter hard | Best compromise when a part must be moderately bent yet hold shape — gaskets, shields, formed terminals. | 220 | 262 | 25 | 58 HB | 100 % IACS |
Half hard | General-purpose strip/bar temper for stamped contacts and busbar that still needs 90° bends. | 250 | 290 | 14 | 70 HB | 99 % IACS |
H04Default Full hard | Default stocked temper for bar, plate and commutator/busbar profiles — highest strength that still machines and solders easily. | 310 | 345 | 8 | 90 HB | 99 % IACS |
Spring hard | Heavily cold rolled strip for flat springs, contact fingers and EMI gaskets needing resilience. | 345 | 379 | 4 | 95 HB | 98 % IACS |
Hard drawn | Hard-drawn wire/rod for magnet wire, commutator risers and overhead conductors that must resist softening after soldering. | 350 | 400 | 2.5 | 95 HB | 98 % IACS |
Extra spring hard | Maximum cold-rolled strength available in strip; use only for flat parts with very generous bend radii. | 365 | 393 | 3 | 100 HB | 98 % IACS |
What is C10500?
C10500 is a higher-silver variant of oxygen-free copper, specified where conductors must resist softening at elevated temperature. The default hard condition provides 310 MPa yield, 345 MPa tensile, 8 % elongation, 90 HB (50 HRB), 388 W/m·K and 99 % IACS with service to 220 °C, in tempers from OS050/O25 annealed through H80. Machinability is only about 28, resistance welding is poor and the alloy cannot be anodized. C10400 is the lower-silver alternative where softening resistance is less critical. C10500 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F). C10500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi).
What is C10500 used for?
- locomotive/traction motor conductors
- high-temperature electrical windings
- welding cable
Advantages
- Conducts heat well — 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades
- High electrical conductivity — 99 % IACS, better than 95% of copper alloy grades
- Readily welded — 60/100, better than 76% of copper alloy grades
Limitations
- Limited ductility — 8%, worse than 83% of copper alloy grades
C10500 properties
Typical room-temperature values for C10500-H04; bars are the position among copper alloy grades.
Physical3
C10500 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical13
C10500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C10500 is rated for continuous service to 220°C (428 °F). It conducts heat at 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C10500 conducts electricity at 99 % IACS, better than 95% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C10500 takes about 57 MJ of energy and emits 4 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 10%.
Manufacturability8
C10500's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability good (60/100); 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. C10500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C10500
Is C10500 easy to machine?
Gummy and stringy at ~20 % of AISI 1212 — use sharp positive-rake tools, high speed, low feed and generous flood coolant; harder tempers (H04/H08) chip better than annealed.
Can C10500 be welded?
Oxygen-free so no hydrogen embrittlement; GTAW/GMAW with ERCu filler, high preheat (200–500 °C) on thick sections due to the 390 W/m·K conductivity; resistance welding is poor.
Can C10500 be formed, bent or molded?
Excellent cold formability in OS050/O25 (deep draw, spin, coin); interanneal at 400–600 °C — note the Ag raises the recrystallization temperature ~100 °C over pure OF copper.
C10500 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 |
|---|---|---|
| Ag≈10 troy oz/ton minimum silver — raises softening temperature | ≥ 0.03 | 0.04 |
| O≤10 ppm oxygen | ≤ 0 | 5×10⁻⁴ |
| P | ≤ 3×10⁻⁴ | |
| Bi | ≤ 0 | |
| Se | ≤ 0 | |
| Te | ≤ 0 | |
| S | ≤ 0 | |
| Pb | ≤ 5×10⁻⁴ | |
| Fe | ≤ 0 | |
| Ni | ≤ 0 | |
| Zn | ≤ 1×10⁻⁴ | |
| CuCu + Ag ≥ 99.95 % (oxygen-free, no deoxidizers) | ≥ 99.95 (balance) |
What surface finishes work on C10500?
Not anodizable; electroplate Ni/Ag/Sn for contacts, or use bright dip / chemical blackening; polishes to a high luster but tarnishes without lacquer or Sn plating.
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 C10500 cost?
C10500 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.
C10500 — frequently asked
What is C10500 used for?
C10500 is typically used for locomotive/traction motor conductors, high-temperature electrical windings and welding cable. In short: highest-silver oxygen-free copper; best softening resistance; 99 % IACS conductivity.
What is the yield strength of C10500?
C10500 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Strength varies by condition: see the 12 listed tempers.
Is C10500 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Gummy and stringy at ~20 % of AISI 1212 — use sharp positive-rake tools, high speed, low feed and generous flood coolant; harder tempers (H04/H08) chip better than annealed.
Can C10500 be welded?
Yes — weldability is rated good (60/100). Oxygen-free so no hydrogen embrittlement; GTAW/GMAW with ERCu filler, high preheat (200–500 °C) on thick sections due to the 390 W/m·K conductivity; resistance welding is poor.
What surface finishes work on C10500?
Not anodizable; electroplate Ni/Ag/Sn for contacts, or use bright dip / chemical blackening; polishes to a high luster but tarnishes without lacquer or Sn plating.
Can C10500 be formed, bent or molded?
Excellent cold formability in OS050/O25 (deep draw, spin, coin); interanneal at 400–600 °C — note the Ag raises the recrystallization temperature ~100 °C over pure OF copper.
What is the maximum service temperature of C10500?
C10500 is rated for continuous use to about 220°C (428 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C10500-H04 and C10500-M30?
H04 is the default condition — default stocked temper for bar, plate and commutator/busbar profiles — highest strength that still machines and solders easily. M30: extruded rod, tube and profile in the as-pressed state, typically drawn or annealed afterwards. Yield strength is 310 MPa in H04 versus 62 MPa in M30.
How much does C10500 cost?
C10500 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 B170 — Oxygen-Free Electrolytic Copper Refinery Shapes — ASTM International (2019)
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar — ASTM International (2019)
- ASTM B187/B187M — Copper Bus Bar, Rod and Shapes — ASTM International (2020)
- CDA UNS C10500 alloy datasheet (copper.org) — 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.