Copper Alloy C17000-TH04
Precip hard
UNS C17000 · EN CW100C
TH04 = tD04 and precipitation hardened
Maximum-strength condition for flat springs, diaphragms and contact fingers with simple geometry.
Values for the TH04 condition
Other C17000 tempers and conditions
C17000 is listed in 14 conditions; see the grade overview at C17000.
Compare all 14 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Softest supply condition — deep draw, stamp or form complex parts, then age harden. | 240 | 480 | 45 | 110 HB | 17 % IACS |
Solution heat treated and cold worked, quarter hard | Light cold work for parts needing extra stiffness in forming while still bendable before aging. | 480 | 585 | 28 | 145 HB | 17 % IACS |
Solution heat treated and cold worked, half hard | Half-hard strip/rod for moderate forming with higher as-formed strength before age hardening. | 570 | 655 | 15 | 185 HB | 17 % IACS |
Mill hardened | Ready-to-use mill hardened strip: no customer aging, best formability of the TM series. | 620 | 760 | 16 | 22 HRC | 24 % IACS |
Solution heat treated and cold worked, full hard | Fully cold-worked temper for flat springs and contacts that receive only simple bends before aging. | 690 | 760 | 5 | 20 HRC | 17 % IACS |
mill hardened quarter hard | Mill hardened strip balancing forming of moderate bends with mid-level spring strength. | 690 | 830 | 14 | 25 HRC | 24 % IACS |
Mill hardened, half hard | Common connector-strip temper: no heat treat needed, good stress relaxation resistance. | 790 | 900 | 11 | 28 HRC | 24 % IACS |
Mill hardened, full hard | Higher-strength mill hardened strip for stamped springs with generous bend radii. | 860 | 965 | 9 | 30 HRC | 24 % IACS |
mill hardened extra hard | Extra-hard mill hardened temper for high-force contacts where only mild forming is required. | 930 | 1,035 | 7 | 33 HRC | 24 % IACS |
TF00Default Solution heat treated and precipitation hardened | Standard peak-aged bar/rod/plate condition for high-strength machined parts and molds. | 1,000 | 1,140 | 6 | 36 HRC | 23 % IACS |
Mill hardened, extra hard | Strongest mill hardened temper — near TH-level strength with no customer heat treatment. | 1,000 | 1,105 | 6 | 34 HRC | 24 % IACS |
TD01 and precipitation hardened | Formed from TD01 stock and aged — highest strength with some residual ductility. | 1,050 | 1,180 | 5 | 37 HRC | 23 % IACS |
TD02 and precipitation hardened | Aged half-hard strip for springs needing high yield strength and good fatigue life. | 1,085 | 1,220 | 4 | 38 HRC | 23 % IACS |
TH04This page TD04 and precipitation hardened | Maximum-strength condition for flat springs, diaphragms and contact fingers with simple geometry. | 1,120 | 1,255 | 3 | 39 HRC | 23 % IACS |
What is C17000-TH04?
C17000-TH04 is C17000 in the TH04 condition — maximum-strength condition for flat springs, diaphragms and contact fingers with simple geometry. C17000-TH04 has a yield strength of 1,120 MPa (162 ksi) and a tensile strength of 1,255 MPa (182 ksi) — stronger than 100% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 131 GPa (19 Msi). C17000-TH04 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 866°C (1,591 °F). TF00 is the default condition FabDigit quotes; TH04 is available on request or by drawing note.
Advantages
- High strength — 1,120 MPa (162 ksi), better than 100% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Stiff — 131 GPa (19 Msi), better than 91% of copper alloy grades
Limitations
- Limited ductility — 3%, worse than 97% of copper alloy grades
- High embodied carbon — 6.5 kg CO₂/kg, worse than 94% of copper alloy grades
- Limited formability — 12/100, worse than 85% of copper alloy grades
C17000-TH04 properties
Typical room-temperature values for C17000-TH04; 22 are specific to this condition. Other listed values are C17000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C17000-TH04 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 866°C (1,591 °F).
Mechanical16
C17000-TH04 has a yield strength of 1,120 MPa (162 ksi) and a tensile strength of 1,255 MPa (182 ksi) — stronger than 100% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 131 GPa (19 Msi).
Thermal6
C17000-TH04 is rated for continuous service to 200°C (392 °F). It conducts heat at 107 W/m·K (61.8 BTU/hr·ft·°F), better than 58% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C17000-TH04 conducts electricity at 23 % IACS, better than 56% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C17000-TH04 takes about 95 MJ of energy and emits 6.5 kg of CO₂ — more than 95% of copper alloy grades. Typical recycled content is 30%.
Manufacturability8
C17000-TH04's machinability is fair (40/100, better than 57% of copper alloy grades); weldability fair (45/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C17000-TH04
Is C17000 easy to machine?
Machine in the aged (TF00/TH) condition with sharp carbide tools, positive rake and flood coolant; capture all chips/dust — beryllium-bearing particulate requires local exhaust and no dry grinding.
Can C17000 be welded?
Resistance, electron-beam and laser welding are preferred; GTAW is possible with matching filler but the weld zone softens and must be re-solution treated and aged; ventilate fumes.
Can C17000 be formed, bent or molded?
Form in TB00 or TD tempers before precipitation aging (typically ~315–330 °C for 2–3 h); aged material has limited bend ductility and springback is high.
What surface finishes work on C17000?
Takes a high mirror polish for mold inserts; electroless nickel, nickel/gold or silver plating is common for contacts; avoid ammonia-based cleaners to prevent stress-corrosion cracking.
C17000 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 |
|---|---|---|
| Be | 1.6 – 1.79 | 1.7 |
| Co+Niminimum combined cobalt + nickel | ≥ 0.2 | 0.3 |
| Co+Ni+Femaximum combined | ≤ 0.6 | — |
| Curemainder, including listed additions | balance | — |
C17000-TH04 — frequently asked
What is C17000-TH04 used for?
C17000-TH04 is typically used for springs, relay and switch parts and electrical connectors. In short: high-strength beryllium copper; 1000 MPa yield after aging; formable before age hardening.
What is the yield strength of C17000-TH04?
C17000-TH04 has a typical yield strength of 1,120 MPa (162 ksi) and a tensile strength of 1,255 MPa (182 ksi) — stronger than 100% of copper alloy grades. Strength varies by condition: see the 14 listed tempers.
Is C17000-TH04 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machine in the aged (TF00/TH) condition with sharp carbide tools, positive rake and flood coolant; capture all chips/dust — beryllium-bearing particulate requires local exhaust and no dry grinding.
Can C17000-TH04 be welded?
With care — weldability is rated fair (45/100). Resistance, electron-beam and laser welding are preferred; GTAW is possible with matching filler but the weld zone softens and must be re-solution treated and aged; ventilate fumes.
What surface finishes work on C17000-TH04?
Takes a high mirror polish for mold inserts; electroless nickel, nickel/gold or silver plating is common for contacts; avoid ammonia-based cleaners to prevent stress-corrosion cracking.
Can C17000-TH04 be formed, bent or molded?
Form in TB00 or TD tempers before precipitation aging (typically ~315–330 °C for 2–3 h); aged material has limited bend ductility and springback is high.
What is the maximum service temperature of C17000-TH04?
C17000-TH04 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 C17000-TF00 and C17000-TB00?
TF00 is the default condition — standard peak-aged bar/rod/plate condition for high-strength machined parts and molds. TB00: softest supply condition — deep draw, stamp or form complex parts, then age harden. Yield strength is 1,000 MPa in TF00 versus 240 MPa in TB00.
Sources
- ASTM B194 / B196 / B197 — Beryllium copper strip, rod and wire — ASTM International (2020)
- CDA Alloy C17000 property datasheet — Copper Development Association (2023)
- Alloy 165 (C17000) technical data — Materion Brush Performance Alloys (2022)
- 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.