Copper Alloy C81700
UNS C81700 · ASTM B824
C81700 (ASTM B824) is an age-hardenable low-beryllium cast copper that reaches 655 MPa tensile and 515 MPa yield at 200 HB while retaining 45 % IACS electrical conductivity and 190 W/m·K thermal conductivity.
Reference datasheet — C81700 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
C81700 tempers and conditions
C81700 is supplied in 3 conditions, soft to hard. TF00 is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Pick when heavy machining, straightening or forming is done before the customer performs the precipitation age. | 125 | 330 | 25 | 70 HB | 25 % IACS |
Thermomechanically controlled processed | Pick for low-stress, dimensionally stable parts or when the casting will be heat treated later by the user. | 140 | 310 | 20 | 75 HB | 30 % IACS |
TF00Default Solution heat treated and precipitation hardened | Standard supply condition: full strength, hardness and ~45 % IACS conductivity for tooling, electrodes and bushings. | 515 | 655 | 5 | 20 HRC | 45 % IACS |
What is C81700?
C81700 (ASTM B824) is an age-hardenable low-beryllium cast copper that reaches 655 MPa tensile and 515 MPa yield at 200 HB while retaining 45 % IACS electrical conductivity and 190 W/m·K thermal conductivity. It is used where a casting must conduct heat and resist wear at the same time — mould cores, bushings and continuous-casting dies — supplied as sand, permanent-mould and centrifugal castings in M (as-cast), TB00 (solution-treated) and TF00 (aged) conditions. Elongation is only 5 % and service is limited to about 200 °C, and beryllium-bearing dust demands controlled handling; C81800 gives higher strength and temperature capability at higher cost. C81700 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,030°C (1,886 °F). C81700 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 130 GPa (18.9 Msi).
What is C81700 used for?
- Plastic mold cores
- Bushings
- Bearing components
- Continuous casting dies
Advantages
- High strength — 515 MPa (74.7 ksi), better than 91% of copper alloy grades
- Stiff — 130 GPa (18.9 Msi), better than 89% of copper alloy grades
- Conducts heat well — 190 W/m·K (109.8 BTU/hr·ft·°F), better than 77% of copper alloy grades
- High electrical conductivity — 45 % IACS, better than 77% of copper alloy grades
Limitations
- Limited ductility — 5%, worse than 93% of copper alloy grades
- High embodied carbon — 4.5 kg CO₂/kg, worse than 79% of copper alloy grades
C81700 properties
Typical room-temperature values for C81700-TF00; bars are the position among copper alloy grades.
Physical3
C81700 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical12
C81700 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 130 GPa (18.9 Msi).
Thermal6
C81700 is rated for continuous service to 200°C (392 °F). It conducts heat at 190 W/m·K (109.8 BTU/hr·ft·°F), better than 77% of copper alloy grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
C81700 conducts electricity at 45 % IACS, better than 77% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C81700 takes about 70 MJ of energy and emits 4.5 kg of CO₂ — more than 84% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C81700's machinability is fair (45/100, better than 64% of copper alloy grades); weldability fair (45/100).
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. C81700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C81700
Is C81700 easy to machine?
Machines like a hard bronze — carbide tooling, positive rake, flood coolant; beryllium-containing swarf and dust must be wet-collected and handled under an occupational-health programme.
Can C81700 be welded?
GTAW/GMAW with matching Cu-Be filler is possible under preheat; the heat-affected zone loses ageing response, so re-solution + re-age for full properties.
Can C81700 be formed, bent or molded?
Supplied as sand, permanent-mould or centrifugal castings with good fluidity; solution treat ~790–815 °C, water quench, then age ~480–500 °C for 2–3 h.
C81700 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 |
|---|---|---|
| Below-beryllium level; verify against current CDA/ASTM B770 registration | 0.4 – 0.8 | 0.6 |
| CoCo (may be partly replaced by Ni) as grain refiner/hardener | 2.4 – 2.7 | 2.5 |
| Agsilver addition raises softening resistance | 0.9 – 1.1 | 1 |
| Si | ≤ 0.2 | |
| Fe | ≤ 0.1 | |
| Al | ≤ 0.1 | |
| CuCu (incl. Ag) approx. 94 % min | balance |
What surface finishes work on C81700?
Not anodisable; polishes to a bright copper finish and takes Ni/Cr or electroless-nickel plating, chemical blackening or clear lacquer for tarnish control.
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 C81700 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B824
How much does C81700 cost?
C81700 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.
C81700 — frequently asked
What is C81700 used for?
C81700 is typically used for plastic mold cores, bushings, bearing components and continuous casting dies. In short: lower-cost cast beryllium copper; wear resistance with 45 % IACS; age-hardenable cast tooling alloy.
What is the yield strength of C81700?
C81700 has a typical yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 91% of copper alloy grades. Strength varies by condition: see the 3 listed tempers.
Is C81700 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Machines like a hard bronze — carbide tooling, positive rake, flood coolant; beryllium-containing swarf and dust must be wet-collected and handled under an occupational-health programme.
Can C81700 be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW with matching Cu-Be filler is possible under preheat; the heat-affected zone loses ageing response, so re-solution + re-age for full properties.
What surface finishes work on C81700?
Not anodisable; polishes to a bright copper finish and takes Ni/Cr or electroless-nickel plating, chemical blackening or clear lacquer for tarnish control.
Can C81700 be formed, bent or molded?
Supplied as sand, permanent-mould or centrifugal castings with good fluidity; solution treat ~790–815 °C, water quench, then age ~480–500 °C for 2–3 h.
What is the maximum service temperature of C81700?
C81700 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 C81700-TF00 and C81700-TB00?
TF00 is the default condition — standard supply condition: full strength, hardness and ~45 % IACS conductivity for tooling, electrodes and bushings. TB00: pick when heavy machining, straightening or forming is done before the customer performs the precipitation age. Yield strength is 515 MPa in TF00 versus 125 MPa in TB00.
How much does C81700 cost?
C81700 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 B770 — Copper-Beryllium Alloy Sand Castings for General Applications — ASTM International (2019)
- ASTM B824 — General Requirements for Copper Alloy Castings — ASTM International (2021)
- CDA Cast Copper Alloy Datasheets (C817xx / C820xx family) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.