Copper Alloy C85900
UNS C85900 · ASTM B584
C85900 is a cast yellow brass in the ASTM B584 family with a balanced Cu-Zn composition, available in M01, M02, M05, M04 and M07 conditions.
Reference datasheet — C85900 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the M01 condition
C85900 tempers and conditions
C85900 is supplied in 5 conditions, soft to hard. M01 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M01Default As sand cast | Standard general-purpose condition for valve bodies, fittings and ornamental castings in small to medium lots. | 115 | 290 | 25 | 60 HB | 26 % IACS |
As centrifugally cast | Choose for bushings, sleeves and rings where a denser, more sound wall than sand casting is needed. | 125 | 310 | 25 | 65 HB | 26 % IACS |
As plaster cast | Medium-volume parts needing better surface finish, closer tolerance and a finer grain than sand casting. | 130 | 320 | 22 | 68 HB | 26 % IACS |
As continuous cast | Bar, tube and hollow stock for machined parts — sound, uniform structure with best machining consistency. | 130 | 315 | 22 | 68 HB | 26 % IACS |
As pressure die cast | High-volume thin-wall hardware and fittings; highest strength but lowest ductility and possible porosity in thick sections. | 195 | 370 | 15 | 85 HB | 25 % IACS |
What is C85900?
C85900 is a cast yellow brass in the ASTM B584 family with a balanced Cu-Zn composition, available in M01, M02, M05, M04 and M07 conditions. It is used for general hardware and decorative castings where moderate strength and easy machining matter more than high load capacity, typically 290 MPa tensile strength, 115 MPa yield, 25% elongation and 60 HB with a machinability rating of 80. It is a casting alloy only, cannot be fusion welded, and will tarnish or dezincify without protection. C85500 offers higher strength if 290 MPa is not enough. C85900 has a density of 8.4 g/cm³ (0.303 lb/in³), lighter than 75% of copper alloy grades. It melts at 875°C (1,607 °F). C85900 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 97 GPa (14.1 Msi).
What is C85900 used for?
- general hardware castings
- decorative fittings
- plumbing components
Advantages
- Low embodied carbon — 3.2 kg CO₂/kg, better than 92% of copper alloy grades
- Easy to machine — 80/100, better than 86% of copper alloy grades
Limitations
- Needs corrosion protection — 45/100, worse than 98% of copper alloy grades
- Limited formability — 10/100, worse than 89% of copper alloy grades
- Low stiffness — 97 GPa (14.1 Msi), worse than 88% of copper alloy grades
- Low strength — 115 MPa (16.7 ksi), worse than 80% of copper alloy grades
C85900 properties
Typical room-temperature values for C85900-M01; bars are the position among copper alloy grades.
Physical3
C85900 has a density of 8.4 g/cm³ (0.303 lb/in³), lighter than 75% of copper alloy grades. It melts at 875°C (1,607 °F).
Mechanical12
C85900 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
C85900 is rated for continuous service to 200°C (392 °F). It conducts heat at 85 W/m·K (49.1 BTU/hr·ft·°F), better than 52% of copper alloy grades. Thermal expansion is 21 µm/m·K (11.7 µin/in·°F).
Electrical3
C85900 conducts electricity at 26 % IACS, better than 63% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of C85900 takes about 45 MJ of energy and emits 3.2 kg of CO₂ — less than 97% of copper alloy grades. Typical recycled content is 90%.
Manufacturability8
C85900's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (30/100); formability not recommended (10/100).
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. C85900 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C85900
Is C85900 easy to machine?
Free-cutting behaviour with sharp positive-rake carbide or HSS tooling, high speeds, light feeds and chip-breaking geometry; little coolant needed.
Can C85900 be welded?
Fusion welding is not recommended (zinc volatilisation, lead hot cracking) — join by brazing or soft soldering, and use local exhaust for Zn fume.
Can C85900 be formed, bent or molded?
Cast only, not a wrought alloy: excellent fluidity, feed with adequate risers, degas the melt and control Zn loss; typical pour 1000–1060 °C.
C85900 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 |
|---|---|---|
| Cuyellow brass casting range; confirm against the current CDA/UNS registration sheet | 58 – 64 | 61 |
| Sn | 0.2 – 1.5 | 0.8 |
| Pbmachinability addition; low-lead pours are made to plumbing rules | 0.5 – 1.5 | 1 |
| Fe | ≤ 0.7 | 0.2 |
| Al | ≤ 0.8 | 0.2 |
| Ni | ≤ 1 | |
| Mn | ≤ 0.5 | |
| Znremainder, nominally 33–40 % | balance |
What surface finishes work on C85900?
Buffs to a bright yellow finish, takes Ni/Cr and clear lacquer well; passivate with benzotriazole or chromate to slow tarnish. 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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C85900 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B584
How much does C85900 cost?
C85900 is a premium-cost copper alloy ($$$), cheaper than about 51% 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.
C85900 — frequently asked
What is C85900 used for?
C85900 is typically used for general hardware castings, decorative fittings and plumbing components. In short: free-cutting general castings; balanced strength and ductility; casting alloy only.
What is the yield strength of C85900?
C85900 has a typical yield strength of 115 MPa (16.7 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 80% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C85900 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Free-cutting behaviour with sharp positive-rake carbide or HSS tooling, high speeds, light feeds and chip-breaking geometry; little coolant needed.
Can C85900 be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is not recommended (zinc volatilisation, lead hot cracking) — join by brazing or soft soldering, and use local exhaust for Zn fume.
What surface finishes work on C85900?
Buffs to a bright yellow finish, takes Ni/Cr and clear lacquer well; passivate with benzotriazole or chromate to slow tarnish. Anodizing is not applicable.
Can C85900 be formed, bent or molded?
Cast only, not a wrought alloy: excellent fluidity, feed with adequate risers, degas the melt and control Zn loss; typical pour 1000–1060 °C.
What is the maximum service temperature of C85900?
C85900 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 C85900-M01 and C85900-M04?
M01 is the default condition — standard general-purpose condition for valve bodies, fittings and ornamental castings in small to medium lots. M04: high-volume thin-wall hardware and fittings; highest strength but lowest ductility and possible porosity in thick sections. Yield strength is 115 MPa in M01 versus 195 MPa in M04.
How much does C85900 cost?
C85900 is a premium-cost copper alloy ($$$), cheaper than about 51% 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.
Sources
- ASTM B584 — Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- ASTM B176 — Copper-Alloy Die Castings — ASTM International (2018)
- CDA Standard Designations / Alloy Datasheets for Cast Yellow Brasses — Copper Development Association (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; 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.