Copper Alloy C81540-M05
Finish state
UNS C81540 · ASTM B824
M05 = as plaster cast
Chill-cast blanks with finer structure than sand; still normally aged to TF00 before use.
Values for the M05 condition
Other C81540 tempers and conditions
C81540 is listed in 5 conditions; see the grade overview at C81540.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Soft, supersaturated interim condition — machine or straighten here, then age to TF00. | 150 | 330 | 30 | 80 HB | 20 % IACS |
As centrifugally cast | Raw foundry condition; strength and conductivity are both low until heat treated — rarely used in service. | 170 | 350 | 22 | 90 HB | 28 % IACS |
M05This page As plaster cast | Chill-cast blanks with finer structure than sand; still normally aged to TF00 before use. | 185 | 380 | 20 | 100 HB | 30 % IACS |
As continuous cast | Continuous-cast bar/tube stock for machined electrode holders; heat treat after rough machining. | 190 | 390 | 20 | 105 HB | 32 % IACS |
TF00Default Solution heat treated and precipitation hardened | Standard supplied condition for electrode holders, welding arms and mold inserts — full strength plus 45–55% IACS. | 480 | 620 | 11 | 185 HB | 50 % IACS |
What is C81540-M05?
C81540-M05 is C81540 supplied in the M05 condition — chill-cast blanks with finer structure than sand; still normally aged to TF00 before use. C81540-M05 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 58% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 128 GPa (18.6 Msi). C81540-M05 has a density of 8.61 g/cm³ (0.311 lb/in³), lighter than 58% of copper alloy grades. It melts at 1,030°C (1,886 °F). TF00 is the default condition FabDigit quotes; M05 is available on request or by drawing note.
Advantages
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
Limitations
- Limited formability — 15/100, worse than 79% of copper alloy grades
C81540-M05 properties
Typical room-temperature values for C81540-M05; 21 are specific to this condition. Other listed values are C81540 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C81540-M05 has a density of 8.61 g/cm³ (0.311 lb/in³), lighter than 58% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical14
C81540-M05 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 58% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 128 GPa (18.6 Msi).
Thermal6
C81540-M05 is rated for continuous service to 300°C (572 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), better than 72% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C81540-M05 conducts electricity at 30 % IACS, better than 71% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C81540-M05 takes about 58 MJ of energy and emits 3.8 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 45%.
Manufacturability7
C81540-M05's machinability is good (60/100, better than 74% of copper alloy grades); weldability fair (45/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C81540-M05
Is C81540 easy to machine?
Machines like a tough medium-hard bronze — sharp positive-rake carbide, high speed, moderate feed and flood coolant; rough in TB00/as-cast and finish after aging to hold size.
Can C81540 be welded?
GTAW/GMAW with matching or Cu-Si filler is possible but the heat-affected zone over-ages and loses hardness; re-solution-treat and age critical parts, and prefer brazing/mechanical joints for repairs.
Can C81540 be formed, bent or molded?
Supplied as sand, permanent-mold or continuous castings; feed heavily and keep melt low in Fe/S — cold forming is essentially limited to light straightening in the TB00 condition.
What surface finishes work on C81540?
Takes a good mechanical polish for mold surfaces and can be nickel- or chrome-plated for wear/release; no anodizing — leave a bare oxide or oil film for electrical contact faces.
C81540 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 |
|---|---|---|
| Ni | 2 – 3 | 2.5 |
| Si | 0.4 – 0.8 | 0.6 |
| Cr | 0.1 – 0.6 | 0.35 |
| Feimpurity limit | ≤ 0.15 | — |
| Alimpurity limit | ≤ 0.1 | — |
| Pbimpurity limit | ≤ 0.02 | — |
| CuCu incl. Ag; Cu + named elements 99.5 % min | ≥ 93.6 (balance) | — |
C81540-M05 — frequently asked
What is C81540-M05 used for?
C81540-M05 is typically used for resistance welding wheels, continuous-casting mold segments and high-load electrical castings. In short: strongest cast high-copper; 620 MPa at 50 % IACS; welding-wheel casting alloy.
What is the yield strength of C81540-M05?
C81540-M05 has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 58% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C81540-M05 easy to machine?
Reasonably — machinability is rated good (60/100, better than 74% of copper alloy grades). Machines like a tough medium-hard bronze — sharp positive-rake carbide, high speed, moderate feed and flood coolant; rough in TB00/as-cast and finish after aging to hold size.
Can C81540-M05 be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW with matching or Cu-Si filler is possible but the heat-affected zone over-ages and loses hardness; re-solution-treat and age critical parts, and prefer brazing/mechanical joints for repairs.
What surface finishes work on C81540-M05?
Takes a good mechanical polish for mold surfaces and can be nickel- or chrome-plated for wear/release; no anodizing — leave a bare oxide or oil film for electrical contact faces.
Can C81540-M05 be formed, bent or molded?
Supplied as sand, permanent-mold or continuous castings; feed heavily and keep melt low in Fe/S — cold forming is essentially limited to light straightening in the TB00 condition.
What is the maximum service temperature of C81540-M05?
C81540-M05 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C81540-TF00 and C81540-TB00?
TF00 is the default condition — standard supplied condition for electrode holders, welding arms and mold inserts — full strength plus 45–55% IACS. TB00: soft, supersaturated interim condition — machine or straighten here, then age to TF00. Yield strength is 480 MPa in TF00 versus 150 MPa in TB00.
Sources
- ASTM B824 — General Requirements for Copper Alloy Castings — ASTM International (2021)
- CDA Alloy Data Sheet C81540 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- RWMA Bulletin 16 — Resistance Welding Electrode Materials (Class 3) — AWS/RWMA (2015)
- High-conductivity Cu-Ni-Si-Cr casting/electrode alloy datasheets — various copper foundries (2023)
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.