Copper Alloy CC212E-GM
Finish state
EN CC212E
GM = permanent (chill/gravity die) cast
Chill casting of smaller repeat parts: finer structure, higher proof strength and better surface than sand casting.
Values for the GM condition
Other CC212E tempers and conditions
CC212E is listed in 5 conditions; see the grade overview at CC212E.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress relieved | Standard post-weld/post-casting anneal for propellers: relieves residual stress and improves resistance to stress-corrosion cracking with a small strength loss. | 300 | 670 | 28 | 170 HB | 3 % IACS |
GSDefault Sand cast | Standard route for large propellers and heavy marine castings; lowest guaranteed proof strength but widely available in any size. | 320 | 700 | 25 | 180 HB | 3 % IACS |
GMThis page Permanent (chill/gravity die) cast | Chill casting of smaller repeat parts: finer structure, higher proof strength and better surface than sand casting. | 340 | 720 | 24 | 185 HB | 3 % IACS |
Centrifugally cast | Bushings, sleeves and rings — dense, porosity-free wall with the highest ductility of the casting routes. | 345 | 730 | 26 | 185 HB | 3 % IACS |
Continuously cast | Continuous-cast bar/tube stock for machined bushings, nuts and wear parts; consistent properties and good machining stock removal. | 345 | 730 | 26 | 185 HB | 3 % IACS |
What is CC212E-GM?
CC212E-GM is CC212E supplied in the GM condition — chill casting of smaller repeat parts: finer structure, higher proof strength and better surface than sand casting. CC212E-GM has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 71% of copper alloy grades. Elongation at break is 24% and the elastic modulus is 117 GPa (17 Msi). CC212E-GM has a density of 7.5 g/cm³ (0.271 lb/in³), lighter than 98% of copper alloy grades. It melts at 870°C (1,598 °F). GS is the default condition FabDigit quotes; GM is available on request or by drawing note.
Advantages
- Lightweight — 7.5 g/cm³ (0.271 lb/in³), better than 98% of copper alloy grades
- Good corrosion resistance — 82/100, better than 98% of copper alloy grades
- Readily welded — 70/100, better than 85% of copper alloy grades
Limitations
- Low electrical conductivity — 3 % IACS, worse than 100% of copper alloy grades
- Poor heat conductor — 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 99% of copper alloy grades
CC212E-GM properties
Typical room-temperature values for CC212E-GM; 21 are specific to this condition. Other listed values are CC212E reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CC212E-GM has a density of 7.5 g/cm³ (0.271 lb/in³), lighter than 98% of copper alloy grades. It melts at 870°C (1,598 °F).
Mechanical15
CC212E-GM has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 71% of copper alloy grades. Elongation at break is 24% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
CC212E-GM is rated for continuous service to 250°C (482 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 99% of copper alloy grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
CC212E-GM conducts electricity at 3 % IACS, worse than 100% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of CC212E-GM takes about 58 MJ of energy and emits 4 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
CC212E-GM's machinability is fair (45/100, better than 64% of copper alloy grades); weldability very good (70/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CC212E-GM
Is CC212E easy to machine?
Tough, gummy chips — use rigid setups, positive-rake carbide, moderate speed with heavy feed and flood coolant; rating roughly half of free-cutting brass.
Can CC212E be welded?
Readily GTAW/GMAW welded and weld-repaired with matching Mn-Al bronze filler; preheat 150–250 °C on heavy sections and stress relieve at ~650 °C afterwards.
Can CC212E be formed, bent or molded?
Casting alloy only — no cold forming; design for quiet bottom gating, generous risers and controlled cooling to avoid shrinkage and hot tearing in thick propeller blades.
What surface finishes work on CC212E?
Grinds and polishes to a bright bronze finish; pickle to remove aluminium oxide before painting or antifouling; not anodizable, and cathodic protection is normally used in seawater service.
CC212E 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 |
|---|---|---|
| Mn | 11 – 14 | 12.5 |
| Al | 7 – 8.5 | 7.8 |
| Fe | 2 – 4 | 3 |
| Ni | 1.5 – 3 | 2.5 |
| Znimpurity limit | ≤ 0.5 | — |
| Snimpurity limit | ≤ 0.1 | — |
| Siimpurity limit | ≤ 0.1 | — |
| Pbimpurity limit | ≤ 0.05 | — |
| Cu | ≥ 68 (balance) | — |
CC212E-GM — frequently asked
What is CC212E-GM used for?
CC212E-GM is typically used for ship propellers, marine stern gear, pump impellers and heavy-duty bearings. In short: strongest cast marine bronze; weld-repairable propeller alloy; 700 MPa with 25% elongation.
What is the yield strength of CC212E-GM?
CC212E-GM has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 71% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is CC212E-GM easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Tough, gummy chips — use rigid setups, positive-rake carbide, moderate speed with heavy feed and flood coolant; rating roughly half of free-cutting brass.
Can CC212E-GM be welded?
Yes — weldability is rated very good (70/100). Readily GTAW/GMAW welded and weld-repaired with matching Mn-Al bronze filler; preheat 150–250 °C on heavy sections and stress relieve at ~650 °C afterwards.
What surface finishes work on CC212E-GM?
Grinds and polishes to a bright bronze finish; pickle to remove aluminium oxide before painting or antifouling; not anodizable, and cathodic protection is normally used in seawater service.
Can CC212E-GM be formed, bent or molded?
Casting alloy only — no cold forming; design for quiet bottom gating, generous risers and controlled cooling to avoid shrinkage and hot tearing in thick propeller blades.
What is the maximum service temperature of CC212E-GM?
CC212E-GM 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 CC212E-GS and CC212E-GZ?
GS is the default condition — standard route for large propellers and heavy marine castings; lowest guaranteed proof strength but widely available in any size. GZ: bushings, sleeves and rings — dense, porosity-free wall with the highest ductility of the casting routes. Yield strength is 320 MPa in GS versus 345 MPa in GZ.
Sources
- EN 1982 — Copper and copper alloys: ingots and castings — CEN (2017)
- CDA alloy datasheet C95700 (manganese aluminium bronze) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (copper alloys in seawater) — ASM International (2005)
- Marine propeller alloy (CuMn11Al8Fe3Ni3-C) casting data — Foundry/propeller manufacturers (2022)
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.