Copper Alloy C81100-M02
Heat-treated state
UNS C81100 · ASTM B824, B369
M02 = as centrifugally cast
For rings, sleeves and bushings needing dense, porosity-free conductive sections.
Values for the M02 condition
Other C81100 tempers and conditions
C81100 is listed in 6 conditions; see the grade overview at C81100.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cast and annealed | Anneal/homogenize when maximum electrical conductivity, dimensional stability and stress relief matter more than strength. | 55 | 165 | 45 | 40 HB | 95 % IACS |
M01Default As sand cast | Default supply condition for one-off and low-volume electrical castings; lowest tooling cost, coarsest grain. | 62 | 172 | 40 | 44 HB | 92 % IACS |
As plaster cast | Higher-volume parts with finer grain, better surface and slightly higher strength than sand cast. | 62 | 179 | 42 | 45 HB | 92 % IACS |
As investment cast | Choose for small, thin-walled contact and terminal bodies where near-net shape saves difficult copper machining. | 62 | 172 | 38 | 44 HB | 91 % IACS |
M02This page As centrifugally cast | For rings, sleeves and bushings needing dense, porosity-free conductive sections. | 65 | 180 | 42 | 46 HB | 92 % IACS |
As continuous cast | Continuous-cast bar and tube stock: densest, most uniform, highest as-cast strength; best when machining a solid conductive blank. | 76 | 195 | 35 | 50 HB | 93 % IACS |
What is C81100-M02?
C81100-M02 is C81100 heat treated to M02 — for rings, sleeves and bushings needing dense, porosity-free conductive sections. C81100-M02 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 98% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi). C81100-M02 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,065°C (1,949 °F). M01 is the default condition FabDigit quotes; M02 is available on request or by drawing note.
Advantages
- High electrical conductivity — 92 % IACS, better than 89% of copper alloy grades
- Conducts heat well — 346 W/m·K (199.9 BTU/hr·ft·°F), better than 87% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
Limitations
- Low strength — 65 MPa (9.43 ksi), worse than 98% of copper alloy grades
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
C81100-M02 properties
Typical room-temperature values for C81100-M02; 20 are specific to this condition. Other listed values are C81100 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C81100-M02 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical14
C81100-M02 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 98% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C81100-M02 is rated for continuous service to 250°C (482 °F). It conducts heat at 346 W/m·K (199.9 BTU/hr·ft·°F), better than 87% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
C81100-M02 conducts electricity at 92 % IACS, better than 89% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C81100-M02 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
C81100-M02's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability fair (45/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C81100-M02
Is C81100 easy to machine?
Gummy and stringy (rating ~20 % of free-cutting brass) — use sharp positive-rake tools, high speed, light feed, generous flood coolant; avoid built-up edge with polished flutes.
Can C81100 be welded?
GTAW/GMAW possible but the huge thermal conductivity demands 400–600 °C preheat and high heat input; brazing or silver soldering is usually preferred for joining conductor castings.
Can C81100 be formed, bent or molded?
Difficult to cast: pure copper is gas-absorbing with poor fluidity and ~4–5 % shrinkage, so use deoxidized melt practice, heavy risering, chills and thick sections; light cold coining/staking is possible after casting.
What surface finishes work on C81100?
Not anodizable — electroplate Ni, Ag or Sn for contact surfaces and tarnish control, or apply clear lacquer/benzotriazole passivation; polishes to a bright finish easily.
C81100 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 |
|---|---|---|
| Other (total)residual impurities; O, P and S kept low to protect conductivity | ≤ 0.3 | 0.1 |
| CuCu (incl. Ag) 99.70 % min per ASTM B824 / CDA C81100; no other elements individually specified | ≥ 99.7 (balance) | — |
C81100-M02 — frequently asked
What is C81100-M02 used for?
C81100-M02 is typically used for electrical connector castings, grounding hardware and conductor fittings. In short: castable 92 % IACS copper; 250 °C service ceiling; demanding foundry practice.
What is the yield strength of C81100-M02?
C81100-M02 has a typical yield strength of 65 MPa (9.43 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 98% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C81100-M02 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and stringy (rating ~20 % of free-cutting brass) — use sharp positive-rake tools, high speed, light feed, generous flood coolant; avoid built-up edge with polished flutes.
Can C81100-M02 be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW possible but the huge thermal conductivity demands 400–600 °C preheat and high heat input; brazing or silver soldering is usually preferred for joining conductor castings.
What surface finishes work on C81100-M02?
Not anodizable — electroplate Ni, Ag or Sn for contact surfaces and tarnish control, or apply clear lacquer/benzotriazole passivation; polishes to a bright finish easily.
Can C81100-M02 be formed, bent or molded?
Difficult to cast: pure copper is gas-absorbing with poor fluidity and ~4–5 % shrinkage, so use deoxidized melt practice, heavy risering, chills and thick sections; light cold coining/staking is possible after casting.
What is the maximum service temperature of C81100-M02?
C81100-M02 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C81100-M01 and C81100-M07?
M01 is the default condition — default supply condition for one-off and low-volume electrical castings; lowest tooling cost, coarsest grain. M07: continuous-cast bar and tube stock: densest, most uniform, highest as-cast strength; best when machining a solid conductive blank. Yield strength is 62 MPa in M01 versus 76 MPa in M07.
Sources
- ASTM B824 — Standard Specification for General Requirements for Copper Alloy Castings — ASTM International (2022)
- ASTM B369 — Copper-Nickel Alloy Castings (referenced designation family) — ASTM International (2021)
- ASTM B601 — Temper Designations for Copper and Copper Alloys — ASTM International (2019)
- CDA Alloy Datasheet C81100 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 15 — Casting (copper alloy foundry practice) — ASM International (2008)
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.