Copper Alloy C10300-O50
Temper
UNS C10300 · EN CW020A
O50 = light annealed
Partially softened temper when a little more strength than dead-soft is wanted with good formability.
Values for the O50 condition
Other C10300 tempers and conditions
C10300 is listed in 14 conditions; see the grade overview at C10300.
Compare all 14 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled and annealed | Heavy plate and bar softened after hot rolling for maximum conductivity, machining stability and formability. | 62 | 225 | 48 | 40 HB | 101 % IACS |
O60Default Soft annealed | Baseline soft temper for maximum conductivity, deep drawing, bending and brazed/vacuum assemblies. | 69 | 230 | 45 | 42 HB | 101 % IACS |
As hot rolled | Mill temper of hot-rolled plate/bar and bus bar where surface finish and flatness matter more than temper control. | 90 | 235 | 40 | 45 HB | 101 % IACS |
O50This page Light annealed | Partially softened temper when a little more strength than dead-soft is wanted with good formability. | 100 | 240 | 40 | 48 HB | 101 % IACS |
1/8 hard | Very light cold work for gaskets and formed parts needing slightly more spring-back control than annealed. | 170 | 250 | 30 | 60 HB | 100.5 % IACS |
Light drawn | Lightly drawn tube or rod: stiffer than annealed but still bendable by hand tooling. | 180 | 260 | 25 | 70 HB | 100 % IACS |
Quarter hard | Quarter-hard strip/sheet balancing moderate strength with 90° bending in most directions. | 205 | 262 | 25 | 68 HB | 100 % IACS |
Half hard | Most-stocked cold-worked sheet/bar temper: usable strength with limited forming (gentle bends). | 245 | 280 | 14 | 78 HB | 100 % IACS |
Three-quarter hard | Intermediate step to full hard when a flatter, stiffer strip is needed but full hard is too brittle to form. | 265 | 295 | 10 | 85 HB | 99.5 % IACS |
Hard drawn | Drawn-to-size hard rod/wire/tube for rigid conductors, machined electrodes and pressure tubing. | 275 | 315 | 10 | 90 HB | 99 % IACS |
Full hard | Standard hard temper for bus bar, terminals and flat parts needing stiffness and flatness with minimal forming. | 280 | 315 | 6 | 92 HB | 99 % IACS |
Extra hard | Extra-hard strip for flat springs, contacts and stamped parts where elastic stiffness dominates. | 315 | 345 | 4 | 100 HB | 98.5 % IACS |
Spring hard | Spring temper strip for conductive springs, shields and clips; forming limited to large-radius bends. | 340 | 365 | 4 | 105 HB | 98 % IACS |
Extra spring hard | Maximum cold-worked strength for thin conductive spring strip; essentially non-formable and softens easily on heating. | 350 | 380 | 3 | 110 HB | 97.5 % IACS |
What is C10300-O50?
C10300-O50 is C10300 in the O50 temper — partially softened temper when a little more strength than dead-soft is wanted with good formability. C10300-O50 has a yield strength of 100 MPa (14.5 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 87% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 117 GPa (17 Msi). C10300-O50 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). O60 is the default condition FabDigit quotes; O50 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
- Readily welded — 85/100, better than 95% of copper alloy grades
- Forms and bends easily — 90/100, better than 89% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
Limitations
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Low strength — 100 MPa (14.5 ksi), worse than 87% of copper alloy grades
C10300-O50 properties
Typical room-temperature values for C10300-O50; 20 are specific to this condition. Other listed values are C10300 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C10300-O50 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
C10300-O50 has a yield strength of 100 MPa (14.5 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 87% of copper alloy grades. Elongation at break is 40% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C10300-O50 is rated for continuous service to 300°C (572 °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 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C10300-O50 conducts electricity at 101 % IACS, better than 98% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C10300-O50 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 25%.
Manufacturability8
C10300-O50's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability excellent (85/100); formability excellent (90/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C10300-O50
Is C10300 easy to machine?
Gummy and low-rated (~20% of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and avoid dwell to prevent smearing.
Can C10300 be welded?
Excellent for GTAW/GMAW/EBW and brazing — the P deoxidation prevents hydrogen embrittlement; high heat input or preheat needed because of the 390 W/m·K conductivity.
Can C10300 be formed, bent or molded?
Annealed temper deep draws, spins and bends superbly; hard tempers need large bend radii and interstage annealing at 400–600 °C.
What surface finishes work on C10300?
Not anodisable — electroplate Ni/Ag/Sn, chemically brighten or polish; bare surfaces tarnish and benefit from lacquer or benzotriazole treatment.
C10300 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 |
|---|---|---|
| Pcontrolled low-phosphorus deoxidation per ASTM B224 / EN Cu-OFP | 0 – 0.01 | 0 |
| Otypical residual oxygen, oxygen-free melting practice | ≤ 0 | 5×10⁻⁴ |
| CuCu + Ag, min; oxygen-free (no deoxidant residue other than P) | ≥ 99.95 (balance) | — |
C10300-O50 — frequently asked
What is C10300-O50 used for?
C10300-O50 is typically used for nuclear waste canisters, high-integrity welded conductors and hydrogen-service piping. In short: weld-grade oxygen-free copper; 101 % IACS conductivity; hydrogen-embrittlement resistant.
What is the yield strength of C10300-O50?
C10300-O50 has a typical yield strength of 100 MPa (14.5 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 87% of copper alloy grades. Strength varies by condition: see the 14 listed tempers.
Is C10300-O50 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and low-rated (~20% of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and avoid dwell to prevent smearing.
Can C10300-O50 be welded?
Yes — weldability is rated excellent (85/100). Excellent for GTAW/GMAW/EBW and brazing — the P deoxidation prevents hydrogen embrittlement; high heat input or preheat needed because of the 390 W/m·K conductivity.
What surface finishes work on C10300-O50?
Not anodisable — electroplate Ni/Ag/Sn, chemically brighten or polish; bare surfaces tarnish and benefit from lacquer or benzotriazole treatment.
Can C10300-O50 be formed, bent or molded?
Annealed temper deep draws, spins and bends superbly; hard tempers need large bend radii and interstage annealing at 400–600 °C.
What is the maximum service temperature of C10300-O50?
C10300-O50 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C10300-O60 and C10300-H10?
O60 is the default condition — baseline soft temper for maximum conductivity, deep drawing, bending and brazed/vacuum assemblies. H10: maximum cold-worked strength for thin conductive spring strip; essentially non-formable and softens easily on heating. Yield strength is 69 MPa in O60 versus 350 MPa in H10.
Sources
- ASTM B224 Standard Classification of Coppers — ASTM International (2021)
- ASTM B152/B152M Copper Sheet, Strip, Plate and Rolled Bar — ASTM International (2019)
- EN 13601 / EN 1652 Copper and copper alloys — Cu-OFP (CW020A) — CEN (2013)
- CDA Alloy Database — C10300 Oxygen-Free Extra-Low Phosphorus Copper — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Copper and Copper 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.