Copper Alloy Cu-OF1
EN CR007A
Cu-OF1 (CR007A) is an oxygen-free copper rod grade held to tighter purity limits than standard Cu-OF, with no cuprous oxide to reduce and therefore no hydrogen ('steam') embrittlement risk during brazing or fusion welding.
Reference datasheet — Cu-OF1 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
Cu-OF1 tempers and conditions
Cu-OF1 is supplied in 6 conditions, soft to hard. H04 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Thermomechanically controlled processed | Unwrought oxygen-free cast stock per EN 1976, supplied for subsequent extrusion, rolling or drawing. | 55 | 170 | 35 | 40 HB | 101 % IACS |
Annealed to 0.050 mm grain size | Grain-size-controlled anneal ordered when subsequent deep drawing, spinning or UHV bakeout behaviour must be reproducible. | 60 | 215 | 52 | 40 HB | 101 % IACS |
Soft annealed | Choose for maximum ductility, deep drawing, cold heading, gasket/seal rings and highest conductivity. | 65 | 220 | 50 | 42 HB | 101 % IACS |
Quarter hard | Light draw for straight, dimensionally stable rod that still bends and forms without cracking. | 180 | 260 | 30 | 68 HB | 100.8 % IACS |
Half hard | Best balance of strength, straightness and remaining ductility for machined electrical hardware and busbar terminals. | 230 | 300 | 20 | 85 HB | 100.5 % IACS |
H04Default Full hard | Standard stocked condition for straight OF copper rod — highest strength and best machining behaviour of the wrought tempers. | 300 | 350 | 12 | 95 HB | 100.2 % IACS |
What is Cu-OF1?
Cu-OF1 (CR007A) is an oxygen-free copper rod grade held to tighter purity limits than standard Cu-OF, with no cuprous oxide to reduce and therefore no hydrogen ('steam') embrittlement risk during brazing or fusion welding. It is specified for demanding electrical and electronic rod work, offering 100.2 % IACS electrical conductivity, 388 W/m·K thermal conductivity and, in the default temper, 350 MPa tensile with 300 MPa yield and 12 % elongation at 95 HB. The practical limits are poor machinability (score 27, roughly 20 % of AISI 1212), softening of hard tempers near the 150 °C maximum service temperature, and higher cost and lead time than ordinary Cu-OF, which is the obvious step down when the extra purity is not needed. Cu-OF1 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F). Cu-OF1 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 61% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 125 GPa (18.1 Msi).
What is Cu-OF1 used for?
- vacuum electronic components
- high-purity electrical rod
- welding electrode stock
Advantages
- High electrical conductivity — 100.2 % IACS, better than 96% of copper alloy grades
- Conducts heat well — 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Readily welded — 68/100, better than 82% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
Cu-OF1 properties
Typical room-temperature values for Cu-OF1-H04; bars are the position among copper alloy grades.
Physical3
Cu-OF1 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F).
Mechanical13
Cu-OF1 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 61% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
Cu-OF1 is rated for continuous service to 150°C (302 °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
Cu-OF1 conducts electricity at 100.2 % IACS, better than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of Cu-OF1 takes about 58 MJ of energy and emits 3.6 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 10%.
Manufacturability8
Cu-OF1's machinability is poor (27/100, worse than 81% of copper alloy grades); weldability good (68/100); 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. Cu-OF1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Cu-OF1
Is Cu-OF1 easy to machine?
Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake carbide or PCD, high speed, light-to-moderate feed and generous flood coolant; avoid dwelling to prevent smearing on UHV sealing faces.
Can Cu-OF1 be welded?
GTAW/EBW/laser weld readily with no risk of hydrogen ('steam') embrittlement, but the very high conductivity needs preheat 200–400 °C, high current and helium-rich shielding on thick sections.
Can Cu-OF1 be formed, bent or molded?
Outstanding cold formability in O60 — deep draw, spin, cold head and bend to tight radii; interanneal at 400–600 °C after heavy reduction, and expect softening of hard tempers above ~150 °C.
Cu-OF1 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 |
|---|---|---|
| O≤5 ppm oxygen — no cuprous oxide network, hydrogen-embrittlement free | ≤ 5×10⁻⁴ | 3×10⁻⁴ |
| Agcounted within the Cu content | ≤ 0 | 0 |
| Bi | ≤ 5×10⁻⁴ | |
| Pb | ≤ 5×10⁻⁴ | |
| S | ≤ 0 | |
| Se | ≤ 3×10⁻⁴ | |
| Te | ≤ 2×10⁻⁴ | |
| Pkept very low to preserve conductivity | ≤ 3×10⁻⁴ | |
| Fe | ≤ 0 | |
| Ni | ≤ 0 | |
| Sn | ≤ 0 | |
| Zn | ≤ 0 | |
| total impuritiessum of named impurities excluding Ag and O | ≤ 0.01 | |
| CuCu incl. Ag, min; oxygen-free refined cathode feed | ≥ 99.99 (balance) |
What surface finishes work on Cu-OF1?
Not anodisable; mirror-polishes and diamond-turns beautifully, and takes electroless/electrolytic Ni, Ag or Au plating — protect bare surfaces with benzotriazole or lacquer against 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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy Cu-OF1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- CR007A
How much does Cu-OF1 cost?
Cu-OF1 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.
Cu-OF1 — frequently asked
What is Cu-OF1 used for?
Cu-OF1 is typically used for vacuum electronic components, high-purity electrical rod and welding electrode stock. In short: tightest-purity oxygen-free copper; no hydrogen embrittlement risk; 100.2 % IACS conductivity.
What is the yield strength of Cu-OF1?
Cu-OF1 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 61% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is Cu-OF1 easy to machine?
Not especially — machinability is rated poor (27/100, worse than 81% of copper alloy grades). Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake carbide or PCD, high speed, light-to-moderate feed and generous flood coolant; avoid dwelling to prevent smearing on UHV sealing faces.
Can Cu-OF1 be welded?
Yes — weldability is rated good (68/100). GTAW/EBW/laser weld readily with no risk of hydrogen ('steam') embrittlement, but the very high conductivity needs preheat 200–400 °C, high current and helium-rich shielding on thick sections.
What surface finishes work on Cu-OF1?
Not anodisable; mirror-polishes and diamond-turns beautifully, and takes electroless/electrolytic Ni, Ag or Au plating — protect bare surfaces with benzotriazole or lacquer against tarnish.
Can Cu-OF1 be formed, bent or molded?
Outstanding cold formability in O60 — deep draw, spin, cold head and bend to tight radii; interanneal at 400–600 °C after heavy reduction, and expect softening of hard tempers above ~150 °C.
What is the maximum service temperature of Cu-OF1?
Cu-OF1 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 Cu-OF1-H04 and Cu-OF1-M?
H04 is the default condition — standard stocked condition for straight OF copper rod — highest strength and best machining behaviour of the wrought tempers. M: unwrought oxygen-free cast stock per EN 1976, supplied for subsequent extrusion, rolling or drawing. Yield strength is 300 MPa in H04 versus 55 MPa in M.
How much does Cu-OF1 cost?
Cu-OF1 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
- EN 1976 — Copper and copper alloys: cast unwrought copper products — CEN (2012)
- EN 13601 — Copper rod, bar and wire for general electrical purposes — CEN (2021)
- EN 1173 — Material condition (temper) designations — CEN (2008)
- ASTM B170 — Oxygen-Free Electrolytic Copper Refinery Shapes — ASTM (2019)
- C10100 / C10200 alloy datasheets — Copper Development Association (copper.org) (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.