Copper Alloy C61300-O25
Temper
UNS C61300
O25 = hot rolled and annealed
Hot-rolled plate given a full anneal — used for condenser tube sheets and marine plate that must be flat, tough and weld-ready.
Values for the O25 condition
Other C61300 tempers and conditions
C61300 is listed in 6 conditions; see the grade overview at C61300.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Softest condition — pick for maximum ductility in severe forming, spinning or heavy cold bending. | 205 | 515 | 45 | 128 HB | — |
O25This page Hot rolled and annealed | Hot-rolled plate given a full anneal — used for condenser tube sheets and marine plate that must be flat, tough and weld-ready. | 215 | 525 | 43 | 133 HB | — |
Annealed | General-purpose annealed plate, sheet and tube; best combination of ductility and dimensional stability for forming and welding. | 220 | 530 | 42 | 135 HB | — |
As-welded deposit | Use for design of overlays and joints made with C61300/ERCuAl-A2 filler; as-deposited metal is slightly stronger and less ductile than annealed plate. | 260 | 540 | 30 | 145 HB | 10.5 % IACS |
M20Default As hot rolled | Standard stocked mill condition for plate, bar and shapes — good strength with ample ductility, no extra heat treatment cost. | 275 | 550 | 35 | 150 HB | — |
Drawn and stress relieved | Highest-strength stocked condition for rod, bar and fasteners — cold drawn then stress relieved for straightness and low residual stress. | 400 | 585 | 28 | 170 HB | — |
What is C61300-O25?
C61300-O25 is C61300 in the O25 temper — hot-rolled plate given a full anneal — used for condenser tube sheets and marine plate that must be flat, tough and weld-ready. C61300-O25 has a yield strength of 215 MPa (31.2 ksi) and a tensile strength of 525 MPa (76.1 ksi) — weaker than 52% of copper alloy grades. Elongation at break is 43% and the elastic modulus is 117 GPa (17 Msi). C61300-O25 has a density of 7.89 g/cm³ (0.285 lb/in³), lighter than 89% of copper alloy grades. It melts at 1,038°C (1,900 °F). M20 is the default condition FabDigit quotes; O25 is available on request or by drawing note.
Advantages
- Readily welded — 78/100, better than 91% of copper alloy grades
- Good corrosion resistance — 75/100, better than 90% of copper alloy grades
- Ductile — tolerates forming and impact — 43%, better than 87% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
- Forms and bends easily — 66/100, better than 79% of copper alloy grades
C61300-O25 properties
Typical room-temperature values for C61300-O25; 10 are specific to this condition. Other listed values are C61300 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C61300-O25 has a density of 7.89 g/cm³ (0.285 lb/in³), lighter than 89% of copper alloy grades. It melts at 1,038°C (1,900 °F).
Mechanical13
C61300-O25 has a yield strength of 215 MPa (31.2 ksi) and a tensile strength of 525 MPa (76.1 ksi) — weaker than 52% of copper alloy grades. Elongation at break is 43% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C61300-O25 is rated for continuous service to 300°C (572 °F). It conducts heat at 62 W/m·K (35.8 BTU/hr·ft·°F), worse than 58% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C61300-O25 conducts electricity at 10.9 % IACS, worse than 71% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (75/100), better than 90% of copper alloy grades.
Sustainability4
Producing a kilogram of C61300-O25 takes about 58 MJ of energy and emits 3.8 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C61300-O25's machinability is poor (33/100, worse than 53% of copper alloy grades); weldability very good (78/100); formability good (66/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C61300-O25
Is C61300 easy to machine?
Machines like a tough, gummy alloy at ~30 % of free-cutting brass: use sharp positive-rake carbide, slow-to-moderate speed, heavy feed and generous coolant to avoid work hardening and built-up edge.
Can C61300 be welded?
Readily GTAW/GMAW welded with ERCuAl-A2 filler, DCEN/AC with argon; preheat 150–200 °C on thick sections, keep interpass low, wire-brush the tenacious alumina film before each pass and avoid oxidizing flames in gas welding.
Can C61300 be formed, bent or molded?
Hot work 700–900 °C; cold form in the O60/O61 temper with generous radii and interstage anneals at 600–700 °C — cold work rate is high, so tooling loads exceed those for brass.
What surface finishes work on C61300?
Not anodizable; polishes to a warm gold sheen but films quickly — passivate/lacquer for appearance, or use as-is in seawater where the protective Al-Sn oxide film is the corrosion barrier. Nickel or chrome plating requires careful alkaline/acid activation of the oxide film.
C61300 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 |
|---|---|---|
| Al | 6 – 7.5 | 7 |
| Fe | 2 – 3 | 2.5 |
| Snsuppresses dealuminification in seawater | 0.2 – 0.5 | 0.35 |
| Mn | ≤ 0.2 | — |
| Ni | ≤ 0.15 | — |
| Si | ≤ 0.1 | — |
| Zn | ≤ 0.1 | — |
| Pb | ≤ 0.01 | — |
| Cu88.5 % min, including Ag | balance | — |
C61300-O25 — frequently asked
What is C61300-O25 used for?
C61300-O25 is typically used for marine fasteners, condenser tubing, structural fittings and bolts and rivets. In short: weldable aluminum bronze; tough marine hardware alloy; machines slower than brass.
What is the yield strength of C61300-O25?
C61300-O25 has a typical yield strength of 215 MPa (31.2 ksi) and a tensile strength of 525 MPa (76.1 ksi) — weaker than 52% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C61300-O25 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 53% of copper alloy grades). Machines like a tough, gummy alloy at ~30 % of free-cutting brass: use sharp positive-rake carbide, slow-to-moderate speed, heavy feed and generous coolant to avoid work hardening and built-up edge.
Can C61300-O25 be welded?
Yes — weldability is rated very good (78/100). Readily GTAW/GMAW welded with ERCuAl-A2 filler, DCEN/AC with argon; preheat 150–200 °C on thick sections, keep interpass low, wire-brush the tenacious alumina film before each pass and avoid oxidizing flames in gas welding.
What surface finishes work on C61300-O25?
Not anodizable; polishes to a warm gold sheen but films quickly — passivate/lacquer for appearance, or use as-is in seawater where the protective Al-Sn oxide film is the corrosion barrier. Nickel or chrome plating requires careful alkaline/acid activation of the oxide film.
Can C61300-O25 be formed, bent or molded?
Hot work 700–900 °C; cold form in the O60/O61 temper with generous radii and interstage anneals at 600–700 °C — cold work rate is high, so tooling loads exceed those for brass.
What is the maximum service temperature of C61300-O25?
C61300-O25 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 C61300-M20 and C61300-HR50?
M20 is the default condition — standard stocked mill condition for plate, bar and shapes — good strength with ample ductility, no extra heat treatment cost. HR50: highest-strength stocked condition for rod, bar and fasteners — cold drawn then stress relieved for straightness and low residual stress. Yield strength is 275 MPa in M20 versus 400 MPa in HR50.
Sources
- ASTM B150/B150M — Aluminum Bronze Rod, Bar, and Shapes — ASTM International (2019)
- ASTM B171/B171M — Copper-Alloy Plate and Sheet for Pressure Vessels, Condensers and Heat Exchangers — ASTM International (2018)
- AWS A5.7/A5.7M — Copper and Copper-Alloy Bare Welding Rods and Electrodes (ERCuAl-A2) — AWS (2007)
- Standards Designation & Alloy Datasheet C61300 — Copper Development Association (copper.org) (2024)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — 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.