Copper Alloy C85700-M04
Finish state
UNS C85700 · ASTM B584
M04 = as pressure die cast
Use for near-net-shape decorative or intricate parts where machining allowance must be minimal.
Values for the M04 condition
Other C85700 tempers and conditions
C85700 is listed in 4 conditions; see the grade overview at C85700.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M01Default As sand cast | Standard stocked condition: sand-cast valve bodies, fittings and hardware to ASTM B584. | 140 | 380 | 18 | 75 HB | 22 % IACS |
M04This page As pressure die cast | Use for near-net-shape decorative or intricate parts where machining allowance must be minimal. | 145 | 380 | 16 | 78 HB | 22 % IACS |
As centrifugally cast | Choose for cylindrical bushings/sleeves needing dense, porosity-free walls. | 160 | 400 | 16 | 80 HB | 22 % IACS |
As plaster cast | Pick for higher strength and better soundness in repetitive small parts (gear blanks, bushings, fittings). | 170 | 415 | 15 | 85 HB | 22 % IACS |
What is C85700-M04?
C85700-M04 is C85700 supplied in the M04 condition — use for near-net-shape decorative or intricate parts where machining allowance must be minimal. C85700-M04 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 72% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 100 GPa (14.5 Msi). C85700-M04 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 875°C (1,607 °F). M01 is the default condition FabDigit quotes; M04 is available on request or by drawing note.
Advantages
- 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
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- Low stiffness — 100 GPa (14.5 Msi), worse than 82% of copper alloy grades
C85700-M04 properties
Typical room-temperature values for C85700-M04; 20 are specific to this condition. Other listed values are C85700 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C85700-M04 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 875°C (1,607 °F).
Mechanical11
C85700-M04 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 72% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
C85700-M04 is rated for continuous service to 200°C (392 °F). It conducts heat at 84 W/m·K (48.5 BTU/hr·ft·°F), better than 51% of copper alloy grades. Thermal expansion is 21.6 µm/m·K (12 µin/in·°F).
Electrical3
C85700-M04 conducts electricity at 22 % IACS, better than 55% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of C85700-M04 takes about 60 MJ of energy and emits 4 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 90%.
Manufacturability6
C85700-M04's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C85700-M04
Is C85700 easy to machine?
Very free-cutting (≈80 % of C36000): use positive-rake, sharp tools, high speed, light feeds; chips break cleanly with lead present.
Can C85700 be welded?
Poor for fusion welding — zinc fume and lead cause porosity/hot cracking; repair by braze or silver-solder with flux and adequate fume extraction.
Can C85700 be formed, bent or molded?
A casting alloy only: good fluidity for sand, permanent-mold, centrifugal and investment casting; use generous risers on heavy sections and avoid cold working.
What surface finishes work on C85700?
Buffs to a bright yellow finish; readily nickel/chrome plated or lacquered — no anodizing, and benzotriazole/lacquer helps prevent tarnish and dezincification.
C85700 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 |
|---|---|---|
| CuASTM B584 C85700 | 58 – 64 | 61 |
| Sn | 0.5 – 1.5 | 1 |
| Pbfree-machining addition; not for lead-free potable water | 0.8 – 1.5 | 1.1 |
| Fe | ≤ 0.7 | — |
| Al | ≤ 0.8 | — |
| Nimax, incl. Co | ≤ 1 | — |
| Mn | ≤ 0.25 | — |
| Sb | ≤ 0.25 | — |
| Zn | ≥ 32 (balance) | — |
C85700-M04 — frequently asked
What is C85700-M04 used for?
C85700-M04 is typically used for gears, bushings and marine hardware. In short: high-strength yellow brass; stronger than red brass; dezincification-prone in service.
What is the yield strength of C85700-M04?
C85700-M04 has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 72% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is C85700-M04 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Very free-cutting (≈80 % of C36000): use positive-rake, sharp tools, high speed, light feeds; chips break cleanly with lead present.
Can C85700-M04 be welded?
Not readily — weldability is rated poor (20/100). Poor for fusion welding — zinc fume and lead cause porosity/hot cracking; repair by braze or silver-solder with flux and adequate fume extraction.
What surface finishes work on C85700-M04?
Buffs to a bright yellow finish; readily nickel/chrome plated or lacquered — no anodizing, and benzotriazole/lacquer helps prevent tarnish and dezincification.
Can C85700-M04 be formed, bent or molded?
A casting alloy only: good fluidity for sand, permanent-mold, centrifugal and investment casting; use generous risers on heavy sections and avoid cold working.
What is the maximum service temperature of C85700-M04?
C85700-M04 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 C85700-M01 and C85700-M05?
M01 is the default condition — standard stocked condition: sand-cast valve bodies, fittings and hardware to ASTM B584. M05: pick for higher strength and better soundness in repetitive small parts (gear blanks, bushings, fittings). Yield strength is 140 MPa in M01 versus 170 MPa in M05.
Sources
- ASTM B584 — Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- CDA Alloy Datasheet C85700 (copper.org) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys (Cast Copper Alloys) — ASM International (1990)
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.