Copper Alloy C80900-M04
Finish state
UNS C80900 · ASTM B369
M04 = as pressure die cast
Continuously cast bar/tube stock — soundest, densest structure; choose when machining pressure-tight or high-conductivity parts from stock.
Values for the M04 condition
Other C80900 tempers and conditions
C80900 is listed in 3 conditions; see the grade overview at C80900.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M01Default As sand cast | Standard as-cast sand casting condition — the usual supply state for electrical and general engineering copper castings. | 62 | 172 | 40 | 44 HB | 92 % IACS |
As centrifugally cast | Chill-cast sections with finer grain — slightly higher strength and hardness than sand cast, for repeat-production electrical parts. | 70 | 190 | 35 | 48 HB | 92 % IACS |
M04This page As pressure die cast | Continuously cast bar/tube stock — soundest, densest structure; choose when machining pressure-tight or high-conductivity parts from stock. | 85 | 200 | 30 | 52 HB | 93 % IACS |
What is C80900-M04?
C80900-M04 is C80900 supplied in the M04 condition — continuously cast bar/tube stock — soundest, densest structure; choose when machining pressure-tight or high-conductivity parts from stock. C80900-M04 has a yield strength of 85 MPa (12.3 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 89% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 118 GPa (17.1 Msi). C80900-M04 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F). M01 is the default condition FabDigit quotes; M04 is available on request or by drawing note.
Advantages
- High electrical conductivity — 93 % IACS, better than 90% of copper alloy grades
- Conducts heat well — 353 W/m·K (204 BTU/hr·ft·°F), better than 89% of copper alloy grades
- Readily welded — 70/100, better than 85% of copper alloy grades
- Ductile — tolerates forming and impact — 30%, better than 75% of copper alloy grades
Limitations
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Low strength — 85 MPa (12.3 ksi), worse than 89% of copper alloy grades
C80900-M04 properties
Typical room-temperature values for C80900-M04; 19 are specific to this condition. Other listed values are C80900 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C80900-M04 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical13
C80900-M04 has a yield strength of 85 MPa (12.3 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 89% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 118 GPa (17.1 Msi).
Thermal6
C80900-M04 is rated for continuous service to 200°C (392 °F). It conducts heat at 353 W/m·K (204 BTU/hr·ft·°F), better than 89% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C80900-M04 conducts electricity at 93 % IACS, better than 90% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C80900-M04 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C80900-M04's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability very good (70/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C80900-M04
Is C80900 easy to machine?
Gummy and low rating (~20 % of free-cutting brass) — use sharp, high-rake, polished-flute tools, high speed, low feed and generous flood coolant to avoid built-up edge.
Can C80900 be welded?
Boron deoxidation gives good GTAW/GMAW weldability with ERCu filler, but high preheat (250–500 °C for thick sections) is required because of the huge thermal conductivity; braze and solder readily.
Can C80900 be formed, bent or molded?
Casting only: needs strong deoxidation/degassing, large risers and chills — pure copper shrinks ~4–5 % and gasses easily, so favour simple, uniformly thick sections.
What surface finishes work on C80900?
Not anodizable; electroplate Ni/Ag/Sn for contact surfaces or apply clear lacquer/benzotriazole to slow tarnishing; polishes bright but is soft and scratches easily.
C80900 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 |
|---|---|---|
| Bboron added as deoxidizer | 0.02 – 0.04 | 0.03 |
| CuCu (including Ag) 99.70 % min | ≥ 99.7 (balance) | — |
C80900-M04 — frequently asked
What is C80900-M04 used for?
C80900-M04 is typically used for marine hardware castings, electrical fittings and terminals, deck and hull fastening hardware, heat-exchanger end castings, grounding and bonding hardware and conductive valve components. In short: boron-deoxidized cast copper; weldable conductive castings; corrosion-resistant copper grade.
What is the yield strength of C80900-M04?
C80900-M04 has a typical yield strength of 85 MPa (12.3 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 89% of copper alloy grades. Strength varies by condition: see the 3 listed tempers.
Is C80900-M04 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and low rating (~20 % of free-cutting brass) — use sharp, high-rake, polished-flute tools, high speed, low feed and generous flood coolant to avoid built-up edge.
Can C80900-M04 be welded?
Yes — weldability is rated very good (70/100). Boron deoxidation gives good GTAW/GMAW weldability with ERCu filler, but high preheat (250–500 °C for thick sections) is required because of the huge thermal conductivity; braze and solder readily.
What surface finishes work on C80900-M04?
Not anodizable; electroplate Ni/Ag/Sn for contact surfaces or apply clear lacquer/benzotriazole to slow tarnishing; polishes bright but is soft and scratches easily.
Can C80900-M04 be formed, bent or molded?
Casting only: needs strong deoxidation/degassing, large risers and chills — pure copper shrinks ~4–5 % and gasses easily, so favour simple, uniformly thick sections.
What is the maximum service temperature of C80900-M04?
C80900-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 C80900-M01 and C80900-M04?
M01 is the default condition — standard as-cast sand casting condition — the usual supply state for electrical and general engineering copper castings. M04: continuously cast bar/tube stock — soundest, densest structure; choose when machining pressure-tight or high-conductivity parts from stock. Yield strength is 62 MPa in M01 versus 85 MPa in M04.
Sources
- Cast Copper Alloys — C80900 property listing — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASTM B824 — General Requirements for Copper Alloy Castings — ASTM International (2021)
- ASM Handbook Vol.13B — Corrosion: Materials (copper alloys) — 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.