Copper Alloy C86500-O50
Temper
UNS C86500 · ASTM B584
O50 = light annealed
Low-temperature (≈250–300 °C) stress relief used before final machining of thin or dimensionally critical castings; strength essentially unchanged.
Values for the O50 condition
Other C86500 tempers and conditions
C86500 is listed in 5 conditions; see the grade overview at C86500.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O50This page Light annealed | Low-temperature (≈250–300 °C) stress relief used before final machining of thin or dimensionally critical castings; strength essentially unchanged. | 185 | 480 | 32 | 100 HB | 22 % IACS |
M01Default As sand cast | Standard as-cast sand-mould condition per ASTM B584; the usual stock for gears, bushings and marine fittings. | 195 | 490 | 30 | 105 HB | 22 % IACS |
As centrifugally cast | Pick for large rings, worm-gear rims and bushings needing sounder, finer-grained metal than sand casting (ASTM B271). | 205 | 510 | 28 | 110 HB | 22 % IACS |
As continuous cast | Continuous-cast solid and hollow bar (ASTM B505) — best choice when machining bushings or sleeves from stock bar. | 205 | 500 | 25 | 110 HB | 22 % IACS |
As plaster cast | For repeat production of smaller parts where the chilled, fine-grained structure gives higher strength and better surface than sand casting. | 215 | 520 | 25 | 115 HB | 22 % IACS |
What is C86500-O50?
C86500-O50 is C86500 in the O50 temper — low-temperature (≈250–300 °C) stress relief used before final machining of thin or dimensionally critical castings; strength essentially unchanged. C86500-O50 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 58% of copper alloy grades. Elongation at break is 32% and the elastic modulus is 105 GPa (15.2 Msi). C86500-O50 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 862°C (1,584 °F). M01 is the default condition FabDigit quotes; O50 is available on request or by drawing note.
Advantages
- Low embodied carbon — 3.2 kg CO₂/kg, better than 92% of copper alloy grades
- Ductile — tolerates forming and impact — 32%, better than 77% of copper alloy grades
Limitations
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
- Limited formability — 18/100, worse than 75% of copper alloy grades
C86500-O50 properties
Typical room-temperature values for C86500-O50; 21 are specific to this condition. Other listed values are C86500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C86500-O50 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 862°C (1,584 °F).
Mechanical15
C86500-O50 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 58% of copper alloy grades. Elongation at break is 32% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C86500-O50 is rated for continuous service to 200°C (392 °F). It conducts heat at 87 W/m·K (50.3 BTU/hr·ft·°F), better than 53% of copper alloy grades. Thermal expansion is 21.6 µm/m·K (12 µin/in·°F).
Electrical3
C86500-O50 conducts electricity at 22 % IACS, better than 55% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C86500-O50 takes about 50 MJ of energy and emits 3.2 kg of CO₂ — less than 89% of copper alloy grades. Typical recycled content is 80%.
Manufacturability8
C86500-O50's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability poor (25/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C86500-O50
Is C86500 easy to machine?
Machines like a tough alpha-beta brass: rating ≈26% of free-cutting brass, use sharp positive-rake carbide, moderate speeds and generous coolant; chips are stringy because Pb is limited.
Can C86500 be welded?
Fusion welding is not recommended (Zn fume, hot cracking); repair by braze welding or silicon-bronze GTAW with low heat input, or use brazing/soldering for joints.
Can C86500 be formed, bent or molded?
Casting alloy — sand, centrifugal, permanent-mould and continuous casting all work well; pour with low turbulence and adequate feeding, and expect ~2% shrinkage plus Zn loss control in melting.
What surface finishes work on C86500?
Not anodisable; use mechanical polishing, chemical brass finishes/black oxide, Ni or Cr plating, or leave bare for marine service with attention to velocity limits.
C86500 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 |
|---|---|---|
| Cu | 55 – 60 | 58 |
| Fegrain refiner / strengthener | 0.4 – 2 | 1 |
| Al | 0.5 – 1.5 | 1 |
| Mn | 0.1 – 1.5 | 0.5 |
| Sn | ≤ 1 | 0.3 |
| Pb | ≤ 0.4 | 0.2 |
| Niincluding Co | ≤ 1 | — |
| Si | ≤ 0.05 | — |
| Zn | ≥ 36 (balance) | — |
C86500-O50 — frequently asked
What is C86500-O50 used for?
C86500-O50 is typically used for gears, marine hardware, bushings and structural castings. In short: workhorse manganese bronze; high ductility for the family; strong marine casting alloy.
What is the yield strength of C86500-O50?
C86500-O50 has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 58% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C86500-O50 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Machines like a tough alpha-beta brass: rating ≈26% of free-cutting brass, use sharp positive-rake carbide, moderate speeds and generous coolant; chips are stringy because Pb is limited.
Can C86500-O50 be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is not recommended (Zn fume, hot cracking); repair by braze welding or silicon-bronze GTAW with low heat input, or use brazing/soldering for joints.
What surface finishes work on C86500-O50?
Not anodisable; use mechanical polishing, chemical brass finishes/black oxide, Ni or Cr plating, or leave bare for marine service with attention to velocity limits.
Can C86500-O50 be formed, bent or molded?
Casting alloy — sand, centrifugal, permanent-mould and continuous casting all work well; pour with low turbulence and adequate feeding, and expect ~2% shrinkage plus Zn loss control in melting.
What is the maximum service temperature of C86500-O50?
C86500-O50 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 C86500-M01 and C86500-M05?
M01 is the default condition — standard as-cast sand-mould condition per ASTM B584; the usual stock for gears, bushings and marine fittings. M05: for repeat production of smaller parts where the chilled, fine-grained structure gives higher strength and better surface than sand casting. Yield strength is 195 MPa in M01 versus 215 MPa in M05.
Sources
- ASTM B584 — Standard Specification for Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- ASTM B271 — Copper-Base Alloy Centrifugal Castings — ASTM International (2020)
- ASTM B505/B505M — Copper Alloy Continuous Castings — ASTM International (2018)
- CDA/UNS Alloy Datasheet C86500 — Copper Development Association (copper.org) (2023)
- 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.