Copper Alloy C62400-O20
Heat-treated state
UNS C62400 · ASTM B150
O20 = hot forged and annealed
For closed-die forgings (valve bodies, gear blanks, flanges) supplied annealed to relieve forging stresses.
Values for the O20 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 | — |
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 |
O20This page 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-O20?
C62400-O20 is C62400 heat treated to O20 — for closed-die forgings (valve bodies, gear blanks, flanges) supplied annealed to relieve forging stresses. C62400-O20 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 18% and the elastic modulus is 110 GPa (16 Msi). C62400-O20 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; O20 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-O20 properties
Typical room-temperature values for C62400-O20; 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-O20 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-O20 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 18% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C62400-O20 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-O20 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-O20 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-O20's machinability is poor (27/100, worse than 81% of copper alloy grades); weldability good (65/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C62400-O20
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-O20 — frequently asked
What is C62400-O20 used for?
C62400-O20 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-O20?
C62400-O20 has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C62400-O20 easy to machine?
Not especially — machinability is rated poor (27/100, worse than 81% 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-O20 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-O20?
Polishes to a golden lustre and can be chemically patinated or lacquered; not anodizable, and electroplating requires careful oxide removal/strike layers.
Can C62400-O20 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-O20?
C62400-O20 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.