Copper Alloy CuAg0.07(OF)-R250
Temper
EN CuAg0.07(OF)
Standard drawn rod temper for machined contacts and screw-machine parts needing straightness and chip control.
Values for the R250 condition
Other CuAg0.07(OF) tempers and conditions
CuAg0.07(OF) is listed in 7 conditions; see the grade overview at CuAg0.07(OF).
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
R200Default annealed, soft | Choose for maximum ductility, deep drawing, bending and forming, and for maximum conductivity after brazing. | 70 | 225 | 45 | 45 HB | 100.5 % IACS |
Thermomechanically controlled processed | Mill stock supplied without specified mechanical properties, for customers who will draw, forge or anneal it themselves. | 70 | 210 | 40 | 42 HB | 100 % IACS |
quarter hard, lightly drawn | Light cold work for straight, dimensionally stable rod that still bends without cracking. | 150 | 240 | 30 | 58 HB | 100 % IACS |
half hard | Best balance of strength and formability for busbar, commutator segments and machined electrical parts. | 200 | 265 | 20 | 80 HB | 99.5 % IACS |
R250This page drawn, medium hard | Standard drawn rod temper for machined contacts and screw-machine parts needing straightness and chip control. | 220 | 275 | 15 | 88 HB | 99 % IACS |
hard drawn | Hard-drawn rod/section where strength and softening resistance at 200–300 °C matter most (commutators, contact-wire sections). | 280 | 320 | 8 | 100 HB | 98.5 % IACS |
extra hard / spring drawn wire | Heavily drawn wire and fine sections for windings and springs that must resist stress relaxation after soldering. | 340 | 380 | 3 | 68 HRB | 97.5 % IACS |
What is CuAg0.07(OF)-R250?
CuAg0.07(OF)-R250 is CuAg0.07(OF) in the R250 temper — standard drawn rod temper for machined contacts and screw-machine parts needing straightness and chip control. CuAg0.07(OF)-R250 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 15% and the elastic modulus is 125 GPa (18.1 Msi). CuAg0.07(OF)-R250 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). R200 is the default condition FabDigit quotes; R250 is available on request or by drawing note.
Advantages
- High electrical conductivity — 99 % IACS, better than 95% of copper alloy grades
- Conducts heat well — 385 W/m·K (222.4 BTU/hr·ft·°F), better than 92% of copper alloy grades
CuAg0.07(OF)-R250 properties
Typical room-temperature values for CuAg0.07(OF)-R250; 19 are specific to this condition. Other listed values are CuAg0.07(OF) reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CuAg0.07(OF)-R250 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).
Mechanical12
CuAg0.07(OF)-R250 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 15% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
CuAg0.07(OF)-R250 is rated for continuous service to 250°C (482 °F). It conducts heat at 385 W/m·K (222.4 BTU/hr·ft·°F), better than 92% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
CuAg0.07(OF)-R250 conducts electricity at 99 % IACS, better than 95% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of CuAg0.07(OF)-R250 takes about 57 MJ of energy and emits 3.9 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 5%.
Manufacturability8
CuAg0.07(OF)-R250's machinability is poor (27/100, worse than 81% of copper alloy grades); weldability fair (52/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CuAg0.07(OF)-R250
Is CuAg0.07(OF) easy to machine?
Gummy and stringy like pure copper (≈20 % of AISI 1212) — use sharp positive-rake polished tools, high speed, generous feed and flood coolant; cold-worked tempers (R250/R290) chip much better than annealed.
Can CuAg0.07(OF) be welded?
Excellent for GTAW/EBW/laser and resistance welding with no hydrogen embrittlement risk, but the 390 W/m·K conductivity demands high heat input and 200–400 °C preheat on thick sections; the weld/HAZ reverts to annealed strength.
Can CuAg0.07(OF) be formed, bent or molded?
Outstanding cold formability in R200 — deep drawing, heading, bending to 0T; anneal at 400–600 °C between severe steps, and expect a higher recrystallisation temperature than Cu-ETP because of the silver.
What surface finishes work on CuAg0.07(OF)?
Solders and brazes readily with mild fluxes; electroplate Ni/Ag/Sn for contacts, or passivate/lacquer bright-polished parts since bare copper tarnishes quickly in air.
CuAg0.07(OF) 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 |
|---|---|---|
| Agsilver raises softening/recrystallisation temperature ~100 °C | 0.06 – 0.08 | 0.07 |
| Ooxygen-free, ≤10 ppm | ≤ 0 | 5×10⁻⁴ |
| Pkept low to protect conductivity | ≤ 3×10⁻⁴ | — |
| Bi | ≤ 5×10⁻⁴ | — |
| Pb | ≤ 5×10⁻⁴ | — |
| S | ≤ 0 | — |
| CuCu + Ag ≥ 99.95 %, from Cu-CATH-1 grade cathode | ≥ 99.95 (balance) | — |
CuAg0.07(OF)-R250 — frequently asked
What is CuAg0.07(OF)-R250 used for?
CuAg0.07(OF)-R250 is typically used for vacuum electronic components, high-reliability brazed conductors and aerospace electrical parts. In short: oxygen-free, hydrogen-embrittlement free; 100.5 % IACS rod grade; higher recrystallisation than Cu-ETP.
What is the yield strength of CuAg0.07(OF)-R250?
CuAg0.07(OF)-R250 has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 51% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is CuAg0.07(OF)-R250 easy to machine?
Not especially — machinability is rated poor (27/100, worse than 81% of copper alloy grades). Gummy and stringy like pure copper (≈20 % of AISI 1212) — use sharp positive-rake polished tools, high speed, generous feed and flood coolant; cold-worked tempers (R250/R290) chip much better than annealed.
Can CuAg0.07(OF)-R250 be welded?
With care — weldability is rated fair (52/100). Excellent for GTAW/EBW/laser and resistance welding with no hydrogen embrittlement risk, but the 390 W/m·K conductivity demands high heat input and 200–400 °C preheat on thick sections; the weld/HAZ reverts to annealed strength.
What surface finishes work on CuAg0.07(OF)-R250?
Solders and brazes readily with mild fluxes; electroplate Ni/Ag/Sn for contacts, or passivate/lacquer bright-polished parts since bare copper tarnishes quickly in air.
Can CuAg0.07(OF)-R250 be formed, bent or molded?
Outstanding cold formability in R200 — deep drawing, heading, bending to 0T; anneal at 400–600 °C between severe steps, and expect a higher recrystallisation temperature than Cu-ETP because of the silver.
What is the maximum service temperature of CuAg0.07(OF)-R250?
CuAg0.07(OF)-R250 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 CuAg0.07(OF)-R200 and CuAg0.07(OF)-R360?
R200 is the default condition — choose for maximum ductility, deep drawing, bending and forming, and for maximum conductivity after brazing. R360: heavily drawn wire and fine sections for windings and springs that must resist stress relaxation after soldering. Yield strength is 70 MPa in R200 versus 340 MPa in R360.
Sources
- EN 1977 — Copper and copper alloys: copper drawing stock (wire rod) — CEN (2013)
- EN 13601 — Copper and copper alloys: copper rod, bar and wire for general electrical purposes — CEN (2021)
- ASTM B152/B187 and CDA alloy sheet C10700 (silver-bearing oxygen-free copper) — ASTM / Copper Development Association (2019)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (copper alloys) — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.