Copper Alloy C10200-OS025
Temper
UNS C10200 · ASTM B170 · EN Cu-OF, CW008A · JIS C1020 · GB TU2
OS025 = annealed to 0.025 mm grain size
Fine-grain anneal for strip that must be formed and then keep a smooth (non-orange-peel) surface.
Values for the OS025 condition
Other C10200 tempers and conditions
C10200 is listed in 14 conditions; see the grade overview at C10200.
Compare all 14 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Most stocked condition: maximum ductility and conductivity for deep drawing, bending, gaskets, vacuum parts and busbar forming. | 69 | 221 | 45 | 45 HB | 101 % IACS |
Hot rolled and annealed | Fully softened hot-rolled/hot-worked oxygen-free copper plate, bar and shapes with maximum ductility and ~101% IACS conductivity. | 69 | 221 | 45 | 45 HB | 101 % IACS |
As hot rolled | Mill condition for thick plate, billet and heavy busbar that will be machined or annealed afterwards. | 75 | 220 | 45 | 45 HB | 101 % IACS |
OS025This page Annealed to 0.025 mm grain size | Fine-grain anneal for strip that must be formed and then keep a smooth (non-orange-peel) surface. | 90 | 235 | 40 | 50 HB | 101 % IACS |
Eighth hard | Slight stiffening over annealed while keeping near-full formability; common for busbar and lead frames that still need bending. | 170 | 250 | 30 | 60 HB | 100.5 % IACS |
Light drawn | Light-drawn OF tube: stiffer than annealed but still bendable, used for vacuum and cryogenic lines. | 195 | 255 | 25 | 70 HB | 100 % IACS |
Quarter hard | Balanced strength/bendability for stamped contacts and shielding that see moderate forming. | 205 | 262 | 25 | 70 HB | 100 % IACS |
Half hard | Standard semi-rigid temper for bar, rod and strip needing handling stiffness with 90° bendability. | 250 | 290 | 14 | 80 HB | 100 % IACS |
Three-quarter hard | Intermediate step to full hard when higher yield is needed but full-hard brittleness in bending is unacceptable. | 275 | 315 | 10 | 88 HB | 99.5 % IACS |
Hard drawn | Hard-drawn seamless tube and rod for pressure lines, waveguides and machined vacuum hardware. | 275 | 315 | 15 | 90 HB | 99 % IACS |
Full hard | Highest routinely stocked strength for flat springs, hard-drawn wire/rod and machined parts needing chip control. | 310 | 345 | 6 | 95 HB | 99 % IACS |
Extra hard | Thin strip/wire needing extra stiffness where forming is limited to gentle radii. | 340 | 365 | 4 | 100 HB | 98.5 % IACS |
Spring hard | Spring-temper strip/wire for contacts, gaskets and RF fingers where elastic limit matters more than ductility. | 350 | 380 | 4 | 105 HB | 98 % IACS |
Extra spring hard | Maximum cold-worked strength available in thin OF copper foil/strip; essentially flat-form only. | 365 | 393 | 3 | 110 HB | 98 % IACS |
What is C10200-OS025?
C10200-OS025 is C10200 in the OS025 temper — fine-grain anneal for strip that must be formed and then keep a smooth (non-orange-peel) surface. C10200-OS025 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 88% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 117 GPa (17 Msi). C10200-OS025 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). O is the default condition FabDigit quotes; OS025 is available on request or by drawing note.
Advantages
- Conducts heat well — 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades
- High electrical conductivity — 101 % IACS, better than 98% of copper alloy grades
- Forms and bends easily — 95/100, better than 94% of copper alloy grades
- Ductile — tolerates forming and impact — 40%, better than 84% of copper alloy grades
- Readily welded — 65/100, better than 80% of copper alloy grades
Limitations
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Low strength — 90 MPa (13.1 ksi), worse than 88% of copper alloy grades
C10200-OS025 properties
Typical room-temperature values for C10200-OS025; 19 are specific to this condition. Other listed values are C10200 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C10200-OS025 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).
Mechanical12
C10200-OS025 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 88% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C10200-OS025 is rated for continuous service to 200°C (392 °F). It conducts heat at 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades. Thermal expansion is 16.9 µm/m·K (9.39 µin/in·°F).
Electrical3
C10200-OS025 conducts electricity at 101 % IACS, better than 98% 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 C10200-OS025 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 20%.
Manufacturability8
C10200-OS025's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability good (65/100); formability excellent (95/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C10200-OS025
Is C10200 easy to machine?
Gummy and stringy — use sharp positive-rake tools, high speed, generous soluble-oil coolant and H02/H04 temper (never annealed) for acceptable chip break; rating ~20 % of free-cutting brass.
Can C10200 be welded?
GTAW/GMAW with ERCu filler, helium or Ar-He shielding and 200–400 °C preheat on thick sections to overcome the heat sink; no hydrogen embrittlement risk, so brazing and hydrogen-furnace brazing are excellent.
Can C10200 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, coin, spin, roll-form); interanneal at 375–650 °C when total reduction exceeds ~60 %.
What surface finishes work on C10200?
Not anodisable — bright-dip/pickle then electroplate Ni, Ag, Sn or Au, or apply benzotriazole passivation/clear lacquer; polishes to a high mirror finish but tarnishes quickly if unprotected.
C10200 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 |
|---|---|---|
| O10 ppm max — defines the 'oxygen-free' grade | ≤ 0 | 5×10⁻⁴ |
| Pnot deliberately added (deoxidiser-free to preserve conductivity) | ≤ 3×10⁻⁴ | — |
| Agcounted as copper | ≈ 0 | 0 |
| Total other impuritiesBi, Pb, S, Se, Te, Sb, As, Fe, Ni, Sn, Zn each held to ppm levels per ASTM B170 | ≤ 0.05 | — |
| CuCu + Ag, oxygen-free; ASTM B170 Grade 2 / UNS C10200 | ≥ 99.95 (balance) | — |
C10200-OS025 — frequently asked
What is C10200-OS025 used for?
C10200-OS025 is typically used for electrical conductors and bus bars, RF cavities and waveguides, vacuum chamber components and seals, hydrogen-brazed heat exchangers, heat sinks and cold plates and transformer and switchgear terminals. In short: oxygen-free pure copper.
What is the yield strength of C10200-OS025?
C10200-OS025 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 88% of copper alloy grades. Strength varies by condition: see the 14 listed tempers.
Is C10200-OS025 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and stringy — use sharp positive-rake tools, high speed, generous soluble-oil coolant and H02/H04 temper (never annealed) for acceptable chip break; rating ~20 % of free-cutting brass.
Can C10200-OS025 be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW with ERCu filler, helium or Ar-He shielding and 200–400 °C preheat on thick sections to overcome the heat sink; no hydrogen embrittlement risk, so brazing and hydrogen-furnace brazing are excellent.
What surface finishes work on C10200-OS025?
Not anodisable — bright-dip/pickle then electroplate Ni, Ag, Sn or Au, or apply benzotriazole passivation/clear lacquer; polishes to a high mirror finish but tarnishes quickly if unprotected.
Can C10200-OS025 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, coin, spin, roll-form); interanneal at 375–650 °C when total reduction exceeds ~60 %.
What is the maximum service temperature of C10200-OS025?
C10200-OS025 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C10200-O and C10200-H10?
O is the default condition — most stocked condition: maximum ductility and conductivity for deep drawing, bending, gaskets, vacuum parts and busbar forming. H10: maximum cold-worked strength available in thin OF copper foil/strip; essentially flat-form only. Yield strength is 69 MPa in O versus 365 MPa in H10.
Can FabDigit make parts in C10200-OS025?
Yes — C10200-OS025 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
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 — Copper Bus Bar, Rod and Shapes — ASTM International (2020)
- EN 13601 / EN 1976 — Cu-OF (CW008A) — CEN (2013)
- CDA/copper.org alloy datasheet C10200 — Copper Development Association (2024)
- 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.