Copper Alloy C62400-O25
Temper
UNS C62400 · ASTM B150
O25 = hot rolled and annealed
Annealed flat product for parts that must be machined or lightly formed after rolling.
Values for the O25 condition
Other C62400 tempers and conditions
C62400 is listed in 7 conditions; see the grade overview at C62400.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot extruded and annealed | Softest supplied condition for extruded rod: lower strength but maximum ductility for subsequent bending, sizing or machining. | 270 | 620 | 20 | 170 HB | — |
O25This page Hot rolled and annealed | Annealed flat product for parts that must be machined or lightly formed after rolling. | 270 | 620 | 20 | 170 HB | 8.5 % IACS |
Hot forged and annealed | For closed-die forgings (valve bodies, gear blanks, flanges) supplied annealed to relieve forging stresses. | 275 | 620 | 18 | 175 HB | 8.5 % IACS |
As hot rolled | Choose for hot-rolled plate and flat products where extruded sections are not available. | 300 | 655 | 14 | 185 HB | — |
M30Default As hot extruded | Standard stock condition for C62400 rod and bar per ASTM B150; best combination of strength, toughness and availability. | 310 | 660 | 14 | 190 HB | 8 % IACS |
Quench hardened and temper annealed | Quench from ~870 °C and temper (~600 °C): highest strength and hardness plus refined β structure that greatly improves resistance to dealuminification — preferred for seawater wear parts. | 415 | 760 | 10 | 22 HRC | — |
Drawn and stress relieved | Cold-drawn (light draft) then stress relieved: highest yield strength with straight, close-tolerance bar for shafts and pins. | 450 | 725 | 10 | 205 HB | — |
What is C62400-O25?
C62400-O25 is C62400 in the O25 temper — annealed flat product for parts that must be machined or lightly formed after rolling. C62400-O25 has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 56% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 110 GPa (16 Msi). C62400-O25 has a density of 7.45 g/cm³ (0.269 lb/in³), lighter than 99% of copper alloy grades. It melts at 1,015°C (1,859 °F). M30 is the default condition FabDigit quotes; O25 is available on request or by drawing note.
Advantages
- Lightweight — 7.45 g/cm³ (0.269 lb/in³), better than 99% of copper alloy grades
- Good corrosion resistance — 76/100, better than 91% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
- Readily welded — 65/100, better than 80% of copper alloy grades
Limitations
- Low electrical conductivity — 8.5 % IACS, worse than 79% of copper alloy grades
C62400-O25 properties
Typical room-temperature values for C62400-O25; 22 are specific to this condition. Other listed values are C62400 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C62400-O25 has a density of 7.45 g/cm³ (0.269 lb/in³), lighter than 99% of copper alloy grades. It melts at 1,015°C (1,859 °F).
Mechanical13
C62400-O25 has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 56% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C62400-O25 is rated for continuous service to 300°C (572 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), worse than 69% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C62400-O25 conducts electricity at 8.5 % IACS, worse than 79% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (76/100), better than 91% of copper alloy grades.
Sustainability4
Producing a kilogram of C62400-O25 takes about 62 MJ of energy and emits 3.9 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C62400-O25's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability good (65/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C62400-O25
Is C62400 easy to machine?
Tough, gummy chips — use rigid setups, positive-rake carbide, moderate speed (~60–120 m/min) with heavy soluble-oil flood; rating only ~20 % of free-cutting brass.
Can C62400 be welded?
GTAW/GMAW with matching aluminium-bronze filler (ERCuAl-A2) works well; preheat 150–200 °C on heavy sections, keep interpass low, remove the tenacious alumina film, and re-heat-treat if dealuminification resistance is critical.
Can C62400 be formed, bent or molded?
Hot work at 700–900 °C (forging/extrusion is the normal route); cold formability is poor, so limit cold bending and stress relieve at ~350–400 °C afterwards.
What surface finishes work on C62400?
Polishes to a golden lustre and can be chemically patinated or lacquered; not anodizable, and electroplating requires careful oxide removal/strike layers.
C62400 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 | 10 – 11.5 | 10.8 |
| Fe | 2 – 4.5 | 3.2 |
| Mn | ≤ 0.3 | 0.1 |
| Si | ≤ 0.25 | — |
| Ninot specified separately; counted with Co where applicable | — | — |
| Pbresidual, typical mill limit | ≤ 0.05 | — |
| Curemainder, 86.0 % min per ASTM B150 | ≥ 86 (balance) | — |
C62400-O25 — frequently asked
What is C62400-O25 used for?
C62400-O25 is typically used for high-strength fasteners, aerospace fittings, gears and structural components. In short: higher-strength aluminum bronze; hot-forged near net shape; low machinability and formability.
What is the yield strength of C62400-O25?
C62400-O25 has a typical yield strength of 270 MPa (39.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 56% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C62400-O25 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Tough, gummy chips — use rigid setups, positive-rake carbide, moderate speed (~60–120 m/min) with heavy soluble-oil flood; rating only ~20 % of free-cutting brass.
Can C62400-O25 be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW with matching aluminium-bronze filler (ERCuAl-A2) works well; preheat 150–200 °C on heavy sections, keep interpass low, remove the tenacious alumina film, and re-heat-treat if dealuminification resistance is critical.
What surface finishes work on C62400-O25?
Polishes to a golden lustre and can be chemically patinated or lacquered; not anodizable, and electroplating requires careful oxide removal/strike layers.
Can C62400-O25 be formed, bent or molded?
Hot work at 700–900 °C (forging/extrusion is the normal route); cold formability is poor, so limit cold bending and stress relieve at ~350–400 °C afterwards.
What is the maximum service temperature of C62400-O25?
C62400-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 C62400-M30 and C62400-HR50?
M30 is the default condition — standard stock condition for C62400 rod and bar per ASTM B150; best combination of strength, toughness and availability. HR50: cold-drawn (light draft) then stress relieved: highest yield strength with straight, close-tolerance bar for shafts and pins. Yield strength is 310 MPa in M30 versus 450 MPa in HR50.
Sources
- ASTM B150/B150M — Aluminum Bronze Rod, Bar and Shapes — ASTM International (2019)
- CDA Alloy Datasheet C62400 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (copper alloys in seawater) — 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.