Copper Alloy C65500 · temper · default condition
Copper Alloy C65500-O
Properties of the O condition, compared with the other C65500 tempers.
Most stocked condition for deep drawing, spinning, severe bending and welded fabrication.
What is C65500-O?
C65500-O is C65500 in the O temper — most stocked condition for deep drawing, spinning, severe bending and welded fabrication. C65500-O has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 63% of copper alloy grades. Elongation at break is 60% and the elastic modulus is 103 GPa (14.9 Msi). C65500-O has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 971°C (1,780 °F).
Advantages
- Ductile — tolerates forming and impact — 60%, better than 99% of copper alloy grades
- Readily welded — 92/100, better than 99% of copper alloy grades
- Forms and bends easily — 92/100, better than 89% of copper alloy grades
- Good corrosion resistance — 72/100, better than 84% of copper alloy grades
Limitations
- Poor heat conductor — 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 86% of copper alloy grades
- Low electrical conductivity — 7 % IACS, worse than 86% of copper alloy grades
C65500-O properties
Typical room-temperature values for C65500-O — 11 properties are specific to this condition; the rest are grade-level values shared by every C65500 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C65500-O has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 971°C (1,780 °F).
Mechanical13
C65500-O has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 63% of copper alloy grades. Elongation at break is 60% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C65500-O is rated for continuous service to 200°C (392 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 86% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C65500-O conducts electricity at 7 % IACS, worse than 86% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 84% of copper alloy grades.
Sustainability4
Producing a kilogram of C65500-O takes about 60 MJ of energy and emits 4 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C65500-O's machinability is poor (28/100, worse than 76% of copper alloy grades); weldability excellent (92/100); formability excellent (92/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C65500 tempers and conditions
C65500 is also supplied in 9 other conditions. The full side-by-side table is on the C65500 overview.
- ODefaultMost stocked condition for deep drawing, spinning, severe bending and welded fabrication.165 MPa yield · 78 HB
- H08Spring temper wire for marine springs, meshes and fasteners needing high elastic limit.650 MPa yield · 97 HRB
- H06Heavily drawn wire and strip for springy clips and high-strength small sections.550 MPa yield · 210 HB
- H04Choose for maximum strength in rod, wire and fasteners where little further forming is required.450 MPa yield · 185 HB
- H02General-purpose strength/ductility compromise for bolts, screws, marine shafting and machined parts.345 MPa yield · 150 HB
- H01Light cold work when moderate strength must be combined with continued bending/forming.275 MPa yield · 120 HB
- M10Hot-forged C65500 silicon bronze cooled in air, giving a recrystallised structure with moderate strength, good ductility and excellent weldability.175 MPa yield · 95 HB
- O50Fine-grain (≈0.025 mm) light anneal of C65500 that restores most ductility while keeping strength and hardness slightly above the fully soft state.170 MPa yield · 85 HB
- O60Fully softened, coarse-grain C65500 with the lowest strength and highest ductility of the annealed tempers, intended for severe cold forming and deep drawing.150 MPa yield · 76 HB
Working with C65500-O
Is C65500 easy to machine?
Rated only ~30 % of free-cutting brass — gummy and work-hardening; use sharp positive-rake tools, rigid setups, moderate speed with generous coolant and avoid dwell.
Can C65500 be welded?
One of the best-welding copper alloys: GTAW/GMAW with ERCuSi-A filler, no preheat on thin sections, keep interpass low and avoid overheating to limit Si oxide film; brazing and silver soldering also good, resistance welding fair.
Can C65500 be formed, bent or molded?
Excellent cold formability in O temper (deep draw, spin, roll thread, cold head); hot work 700–875 °C only, since Si narrows the hot ductility window; anneal 480–700 °C and quench or air cool.
What surface finishes work on C65500?
Takes a bright mechanical polish and accepts statuary/brown chemical patinas, oxidizing dips and clear lacquer; electroplates (Ni, Cr) readily after activation — anodizing is not applicable.
C65500 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 |
|---|---|---|
| Si | 2.8 – 3.8 | 3.1 |
| Mn | 0.5 – 1.3 | 0.9 |
| Fe | ≤ 0.8 | — |
| Zn | ≤ 1.5 | — |
| NiNi + Co, max | ≤ 0.6 | — |
| Sn | ≤ 0.6 | — |
| Pb | ≤ 0.05 | — |
| Curemainder, 94.8 % min incl. Ag | ≥ 94.8 (balance) | — |
C65500-O — frequently asked
What is C65500-O used for?
C65500-O is typically used for silicon bronze fasteners and bolts, propeller shafts, chemical process vessels, anchor chain, underwater structural hardware and welding filler rod. In short: heavy marine structural bronze.
What is the yield strength of C65500-O?
C65500-O has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 63% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C65500-O easy to machine?
Not especially — machinability is rated poor (28/100, worse than 76% of copper alloy grades). Rated only ~30 % of free-cutting brass — gummy and work-hardening; use sharp positive-rake tools, rigid setups, moderate speed with generous coolant and avoid dwell.
Can C65500-O be welded?
Yes — weldability is rated excellent (92/100). One of the best-welding copper alloys: GTAW/GMAW with ERCuSi-A filler, no preheat on thin sections, keep interpass low and avoid overheating to limit Si oxide film; brazing and silver soldering also good, resistance welding fair.
What surface finishes work on C65500-O?
Takes a bright mechanical polish and accepts statuary/brown chemical patinas, oxidizing dips and clear lacquer; electroplates (Ni, Cr) readily after activation — anodizing is not applicable.
Can C65500-O be formed, bent or molded?
Excellent cold formability in O temper (deep draw, spin, roll thread, cold head); hot work 700–875 °C only, since Si narrows the hot ductility window; anneal 480–700 °C and quench or air cool.
What is the maximum service temperature of C65500-O?
C65500-O 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 C65500-O and C65500-H08?
O is the default condition — most stocked condition for deep drawing, spinning, severe bending and welded fabrication. H08: spring temper wire for marine springs, meshes and fasteners needing high elastic limit. Yield strength is 165 MPa in O versus 650 MPa in H08.
Can FabDigit make parts in C65500-O?
Yes — C65500-O is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B98/B98M Copper-Silicon Alloy Rod, Bar and Shapes — ASTM International (2019)
- ASTM B96/B96M Copper-Silicon Alloy Plate, Sheet, Strip and Bar — ASTM International (2016)
- EN 12163/12167 CuSi3Mn (CW116C) — CEN (2016)
- C65500 alloy datasheet (properties, tempers, machinability) — Copper Development Association (copper.org) (2024)
- ASM Handbook Vol.2 — Properties of Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- GB/T 5231 / GB/T 13808 QSi3-1 — (SAC) (2022)
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.