Copper Alloy C65500
UNS C65500 · ASTM B98, B96 · EN CuSi3Mn, CW116C
C65500 is a high-silicon bronze with about 3% Si and 1% Mn (Silicon Bronze A, Everdur), solid-solution strengthened to well above the strength of copper while keeping excellent cold formability, weldability and resistance to seawater and atmospheric corrosion.
Values for the O condition
C65500 tempers and conditions
C65500 is supplied in 10 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Fully softened, coarse-grain C65500 with the lowest strength and highest ductility of the annealed tempers, intended for severe cold forming and deep drawing. | 150 | 395 | 62 | 76 HB | 7 % IACS |
ODefault Annealed | Most stocked condition for deep drawing, spinning, severe bending and welded fabrication. | 165 | 400 | 60 | 78 HB | 7 % IACS |
Light annealed | Fine-grain (≈0.025 mm) light anneal of C65500 that restores most ductility while keeping strength and hardness slightly above the fully soft state. | 170 | 415 | 55 | 85 HB | 7 % IACS |
As hot forged and air cooled | Hot-forged C65500 silicon bronze cooled in air, giving a recrystallised structure with moderate strength, good ductility and excellent weldability. | 175 | 415 | 35 | 95 HB | 7 % IACS |
As hot rolled | Pick for large extruded sections, forging stock and weld-fabricated parts where no temper control is needed. | 190 | 420 | 50 | 90 HB | 7 % IACS |
Quarter hard | Light cold work when moderate strength must be combined with continued bending/forming. | 275 | 470 | 35 | 120 HB | 6.9 % IACS |
Half hard | General-purpose strength/ductility compromise for bolts, screws, marine shafting and machined parts. | 345 | 540 | 22 | 150 HB | 7 % IACS |
Full hard | Choose for maximum strength in rod, wire and fasteners where little further forming is required. | 450 | 660 | 13 | 185 HB | 7 % IACS |
Extra hard | Heavily drawn wire and strip for springy clips and high-strength small sections. | 550 | 740 | 8 | 19 HRC | 6.8 % IACS |
Spring hard | Spring temper wire for marine springs, meshes and fasteners needing high elastic limit. | 650 | 830 | 5 | 21 HRC | 6.7 % IACS |
What is C65500?
C65500 is a high-silicon bronze with about 3% Si and 1% Mn (Silicon Bronze A, Everdur), solid-solution strengthened to well above the strength of copper while keeping excellent cold formability, weldability and resistance to seawater and atmospheric corrosion. It is supplied as rod, wire, strip and plate for fasteners, marine shafts and bolts, chemical vessels, anchor chain, underwater structures, welding filler and architectural trim. Limits are low electrical and thermal conductivity (about 7% IACS), poor machinability (about 30% of free-cutting brass), a narrow hot-working window, and unsuitability for sustained high-temperature loading. C65500 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). C65500 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Elongation at break is 60% and the elastic modulus is 103 GPa (14.9 Msi).
What is C65500 used for?
- Silicon bronze fasteners and bolts
- Propeller shafts
- Chemical process vessels
- Anchor chain
- Underwater structural hardware
- Welding filler rod
- Architectural trim and railings
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 91% 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 properties
Typical room-temperature values for C65500-O; bars are the position among copper alloy grades.
Physical3
C65500 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 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Elongation at break is 60% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C65500 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 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 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's machinability is poor (28/100, worse than 78% 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.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C65500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C65500
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.
Manufacturability
The process limits FabDigit applies to C65500. Every C65500 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair28 / 100 |
|---|---|
| ISO material group | N.5 |
| Cutting speed (rough / finish) | 180 / 220 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 6× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better92 / 100 |
|---|---|
| Weldability | Better92 / 100 |
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) |
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.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Plating
Organic Coating
Equivalent designations
Standards and trade names that resolve to Copper Alloy C65500 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B98B96
- EN / DIN / Werkstoff-Nr.
- CuSi3MnCW116C
- Trade names
- Everdur
- Also called
- High Silicon BronzeSilicon Bronze
- Similar grades
- C6870QSi3-1
How much does C65500 cost?
C65500 is a specialty-cost copper alloy ($$$$$), pricier than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C65500 — frequently asked
What is C65500 used for?
C65500 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?
C65500 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C65500 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% 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 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?
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 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?
C65500 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.
How much does C65500 cost?
C65500 is a specialty-cost copper alloy ($$$$$), pricier than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in C65500?
Yes — C65500 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.