Copper Alloy C64700
UNS C64700 · ASTM B411 · EN CuNi2Si
C64700 is a nickel-silicon bronze (CuNi2Si) from the wrought silicon/aluminum bronze family, strengthened by Ni-Si precipitates and supplied to ASTM B411 as rod, bar, wire and forging stock.
Reference datasheet — C64700 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
C64700 tempers and conditions
C64700 is supplied in 9 conditions, soft to hard. TF00 is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for maximum forming/bending before any age hardening. | 125 | 330 | 45 | 80 HB | 42 % IACS |
Solution heat treated | Choose when parts must be deep-drawn, formed or machined before a customer-performed ageing cycle. | 140 | 340 | 45 | 85 HB | 25 % IACS |
Solution heat treated and cold worked, quarter hard | Light cold work before ageing; used when moderate stiffness plus some remaining formability is needed. | 310 | 415 | 25 | 115 HB | 26 % IACS |
Solution heat treated and cold worked, half hard | Half-hard drawn rod/wire for parts to be aged after light forming or heading. | 380 | 460 | 15 | 135 HB | 26 % IACS |
TF00Default Solution heat treated and precipitation hardened | Standard stocked condition: best balance of strength, ductility and ~38% IACS conductivity for fasteners, bushings and valve stems. | 415 | 550 | 18 | 165 HB | 38 % IACS |
Solution heat treated and cold worked, full hard | Hard-drawn, un-aged stock: good straightness and strength when ageing will be done after machining. | 450 | 515 | 10 | 155 HB | 27 % IACS |
TD01 and precipitation hardened | Light cold work plus ageing when strength above TF00 is needed with reasonable ductility. | 515 | 600 | 14 | 12 HRC | 39 % IACS |
TD02 and precipitation hardened | Half-hard plus age: common for springs, connectors and high-load bushings. | 570 | 655 | 11 | 18 HRC | 40 % IACS |
TD04 and precipitation hardened | Maximum-strength temper for wear parts, high-strength fasteners and welding-electrode holders; lowest ductility. | 655 | 725 | 8 | 22 HRC | 40 % IACS |
What is C64700?
C64700 is a nickel-silicon bronze (CuNi2Si) from the wrought silicon/aluminum bronze family, strengthened by Ni-Si precipitates and supplied to ASTM B411 as rod, bar, wire and forging stock. Engineers specify it where a copper alloy must combine 415 MPa yield and 550 MPa tensile with 38% IACS electrical conductivity, 155 W/m·K thermal conductivity and 165 HB wear resistance, while remaining weldable and corrosion resistant. Service is limited to about 200 °C, the weld heat-affected zone over-ages and must be re-aged, and machinability is only 40. C65100 is the lower-cost option when precipitation-hardened strength is not needed. C64700 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 65% of copper alloy grades. It melts at 1,030°C (1,886 °F). C64700 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 82% of copper alloy grades. Elongation at break is 18% and the elastic modulus is 132 GPa (19.1 Msi).
What is C64700 used for?
- fasteners
- springs
- wear-resistant components
Advantages
- Stiff — 132 GPa (19.1 Msi), better than 93% of copper alloy grades
- Readily welded — 70/100, better than 85% of copper alloy grades
- High strength — 415 MPa (60.2 ksi), better than 82% of copper alloy grades
C64700 properties
Typical room-temperature values for C64700-TF00; bars are the position among copper alloy grades.
Physical3
C64700 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 65% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical13
C64700 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 82% of copper alloy grades. Elongation at break is 18% and the elastic modulus is 132 GPa (19.1 Msi).
Thermal6
C64700 is rated for continuous service to 200°C (392 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 73% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C64700 conducts electricity at 38 % IACS, better than 73% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C64700 takes about 62 MJ of energy and emits 4 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C64700's machinability is fair (40/100, better than 57% of copper alloy grades); weldability very good (70/100); formability 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. C64700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C64700
Is C64700 easy to machine?
Machines like a tough medium-strength bronze (~30 % of free-cutting brass); use sharp positive-rake carbide, high speed, generous coolant — best chip control in the aged TF00/TH condition.
Can C64700 be welded?
GTAW/GMAW with matching or silicon-bronze filler is good; keep heat input low and re-age after welding since the HAZ over-ages and softens.
Can C64700 be formed, bent or molded?
Form, head or draw in the TB00/O61 condition, then age at ~450–500 °C for 2–3 h; cold forming in TH tempers risks cracking.
C64700 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 | 1.6 – 2.2 | 1.9 |
| Si | 0.5 – 0.8 | 0.65 |
| Zn | ≤ 0.5 | |
| Fe | ≤ 0.1 | |
| Pb | ≤ 0.09 | |
| Curemainder, Cu + named elements 99.5 % min (Ag counted as Cu) | balance |
What surface finishes work on C64700?
Not anodizable — polishes to a bright bronze finish and accepts tin, nickel, silver or gold plating; passivate or lacquer to limit atmospheric tarnish.
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 C64700 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B411
- EN / DIN / Werkstoff-Nr.
- CuNi2Si
- Similar grades
- C1860
How much does C64700 cost?
C64700 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.
C64700 — frequently asked
What is C64700 used for?
C64700 is typically used for fasteners, springs and wear-resistant components. In short: age-hardening silicon bronze; strength with 38% IACS; wear-resistant weldable bronze.
What is the yield strength of C64700?
C64700 has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 82% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C64700 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machines like a tough medium-strength bronze (~30 % of free-cutting brass); use sharp positive-rake carbide, high speed, generous coolant — best chip control in the aged TF00/TH condition.
Can C64700 be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW with matching or silicon-bronze filler is good; keep heat input low and re-age after welding since the HAZ over-ages and softens.
What surface finishes work on C64700?
Not anodizable — polishes to a bright bronze finish and accepts tin, nickel, silver or gold plating; passivate or lacquer to limit atmospheric tarnish.
Can C64700 be formed, bent or molded?
Form, head or draw in the TB00/O61 condition, then age at ~450–500 °C for 2–3 h; cold forming in TH tempers risks cracking.
What is the maximum service temperature of C64700?
C64700 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 C64700-TF00 and C64700-O61?
TF00 is the default condition — standard stocked condition: best balance of strength, ductility and ~38% IACS conductivity for fasteners, bushings and valve stems. O61: softest condition for maximum forming/bending before any age hardening. Yield strength is 415 MPa in TF00 versus 125 MPa in O61.
How much does C64700 cost?
C64700 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 B411/B411M — Copper-Nickel-Silicon Alloy Rod and Bar — ASTM International (2020)
- CDA Alloy Datasheet C64700 (UNS) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- GB/T 5231 / JIS H3110 C1860 Corson alloy designations — SAC / JISC (2022)
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.