Copper Alloy C81540
UNS C81540 · ASTM B824
C81540 is a cast high-copper alloy (ASTM B824) strengthened with chromium, nickel and silicon and age hardened in the TF00 condition to 480 MPa yield, 620 MPa tensile, 11 % elongation and 185 HB (92 HRB).
Reference datasheet — C81540 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the TF00 condition
C81540 tempers and conditions
C81540 is supplied in 5 conditions, soft to hard. TF00 is the default FabDigit quotes; the values on this page are for it.
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 |
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?
C81540 is a cast high-copper alloy (ASTM B824) strengthened with chromium, nickel and silicon and age hardened in the TF00 condition to 480 MPa yield, 620 MPa tensile, 11 % elongation and 185 HB (92 HRB). It is chosen where a casting must carry high mechanical and thermal load while still conducting, and is supplied as sand, permanent-mold and continuous castings for welding wheels and mold segments. Conductivity is 50 % IACS with 200 W/m·K and service to 450 °C, below the Cu-Cr grades C81200 and C81300. The heat-affected zone over-ages during welding, and machinability is moderate at 55. C81540 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). C81540 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 11% and the elastic modulus is 131 GPa (19 Msi).
What is C81540 used for?
- resistance welding wheels
- continuous-casting mold segments
- high-load electrical castings
Advantages
- High service temperature — 450°C (842 °F), better than 98% of copper alloy grades
- Stiff — 131 GPa (19 Msi), better than 91% of copper alloy grades
- High strength — 480 MPa (69.6 ksi), better than 88% of copper alloy grades
- High electrical conductivity — 50 % IACS, better than 79% of copper alloy grades
- Conducts heat well — 200 W/m·K (115.6 BTU/hr·ft·°F), better than 78% of copper alloy grades
C81540 properties
Typical room-temperature values for C81540-TF00; bars are the position among copper alloy grades.
Physical3
C81540 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 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 11% and the elastic modulus is 131 GPa (19 Msi).
Thermal6
C81540 is rated for continuous service to 450°C (842 °F). It conducts heat at 200 W/m·K (115.6 BTU/hr·ft·°F), better than 78% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C81540 conducts electricity at 50 % IACS, better than 79% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C81540 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's machinability is good (55/100, better than 71% of copper alloy grades); weldability fair (35/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C81540 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C81540
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.
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) |
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.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C81540 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B824
How much does C81540 cost?
C81540 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C81540 — frequently asked
What is C81540 used for?
C81540 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?
C81540 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 88% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C81540 easy to machine?
Reasonably — machinability is rated good (55/100, better than 71% 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 be welded?
With care — weldability is rated fair (35/100). 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?
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 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?
C81540 is rated for continuous use to about 450°C (842 °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.
How much does C81540 cost?
C81540 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.