Copper Alloy C17450-TH04
Precip hard
UNS C17450 · ASTM B441
TH04 = tD04 and precipitation hardened
Highest-strength rod/bar route: cold draw to hard temper, then age; use where machining precedes minimal forming.
Values for the TH04 condition
Other C17450 tempers and conditions
C17450 is listed in 8 conditions; see the grade overview at C17450.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Softest condition for deep forming or heavy machining before customer-performed age hardening. | 170 | 330 | 35 | 45 HRB | 25 % IACS |
Mill hardened | Pick when the part needs tight-radius bends and only moderate spring force, with no post-forming heat treatment. | 420 | 550 | 18 | 82 HRB | 57 % IACS |
Mill hardened, half hard | Balanced strength/formability for stamped connector springs with medium bend radii. | 515 | 620 | 15 | 9 HRC | 53 % IACS |
Solution heat treated and precipitation hardened | Formed or machined from TB00, then aged in-house; typical for rod, bar and machined contact parts. | 550 | 655 | 15 | 92 HRB | 50 % IACS |
TM04Default Mill hardened, full hard | The standard stocked strip temper: best all-round mix of spring force, conductivity and bendability for high-current contacts. | 600 | 700 | 12 | 93 HRB | 50 % IACS |
Mill hardened, extra hard | Higher contact force and better stress relaxation, at the cost of larger minimum bend radii. | 655 | 760 | 10 | 20 HRC | 48 % IACS |
TH04This page TD04 and precipitation hardened | Highest-strength rod/bar route: cold draw to hard temper, then age; use where machining precedes minimal forming. | 690 | 760 | 10 | 20 HRC | 48 % IACS |
Mill hardened, spring hard | Maximum spring strength of the mill-hardened series; use for flat or gently formed parts needing high contact normal force. | 725 | 825 | 8 | 99 HRB | 45 % IACS |
What is C17450-TH04?
C17450-TH04 is C17450 in the TH04 condition — highest-strength rod/bar route: cold draw to hard temper, then age; use where machining precedes minimal forming. C17450-TH04 has a yield strength of 690 MPa (100 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 96% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 138 GPa (20 Msi). C17450-TH04 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 1,030°C (1,886 °F). TM04 is the default condition FabDigit quotes; TH04 is available on request or by drawing note.
Advantages
- High strength — 690 MPa (100 ksi), better than 96% of copper alloy grades
- Stiff — 138 GPa (20 Msi), better than 95% of copper alloy grades
- Conducts heat well — 200 W/m·K (115.6 BTU/hr·ft·°F), better than 78% of copper alloy grades
- High electrical conductivity — 48 % IACS, better than 78% of copper alloy grades
Limitations
- High embodied carbon — 5.2 kg CO₂/kg, worse than 88% of copper alloy grades
- Limited ductility — 10%, worse than 76% of copper alloy grades
C17450-TH04 properties
Typical room-temperature values for C17450-TH04; 20 are specific to this condition. Other listed values are C17450 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C17450-TH04 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical12
C17450-TH04 has a yield strength of 690 MPa (100 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 96% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 138 GPa (20 Msi).
Thermal6
C17450-TH04 is rated for continuous service to 200°C (392 °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 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C17450-TH04 conducts electricity at 48 % IACS, better than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C17450-TH04 takes about 75 MJ of energy and emits 5.2 kg of CO₂ — more than 88% of copper alloy grades. Typical recycled content is 25%.
Manufacturability7
C17450-TH04's machinability is fair (40/100, better than 57% of copper alloy grades); weldability fair (50/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C17450-TH04
Is C17450 easy to machine?
Machines like a hard bronze (~20 % of AISI 1212) — use sharp carbide, rigid setups and flood coolant; wet-cut and capture all dust/fume because of beryllium exposure limits.
Can C17450 be welded?
Excellent for resistance and laser welding of contacts; GTAW/EBW possible with matching filler but the HAZ over-ages and loses strength unless re-aged, and ventilation for Be fume is mandatory.
Can C17450 be formed, bent or molded?
Stamp and bend in the mill-hardened temper chosen for the bend radius (TM00/TM02 for tight bends); alternatively form in TB00 and age 2–3 h at ~455–480 °C, allowing for slight growth.
What surface finishes work on C17450?
Readily tin-, nickel-, silver- or gold-plated for contact surfaces; solders and brazes well, takes a bright polish, and no anodizing applies.
C17450 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 precipitation hardener | 0.15 – 0.5 | 0.3 |
| Ni | 1 – 1.4 | 1.2 |
| ZrZr addition distinguishes the C17450/C17460 registrations; confirm against the governing ASTM/CDA sheet for the specific supply | 0.1 – 0.5 | 0.25 |
| CuCu + named elements ≥ 99.5 %; other elements by agreement | ≥ 96.9 (balance) | — |
C17450-TH04 — frequently asked
What is C17450-TH04 used for?
C17450-TH04 is typically used for high-current connectors, battery contacts and RF shielding fingers. In short: high-conductivity spring copper; mill-hardened contact strip; beryllium handling required.
What is the yield strength of C17450-TH04?
C17450-TH04 has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 96% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C17450-TH04 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machines like a hard bronze (~20 % of AISI 1212) — use sharp carbide, rigid setups and flood coolant; wet-cut and capture all dust/fume because of beryllium exposure limits.
Can C17450-TH04 be welded?
With care — weldability is rated fair (50/100). Excellent for resistance and laser welding of contacts; GTAW/EBW possible with matching filler but the HAZ over-ages and loses strength unless re-aged, and ventilation for Be fume is mandatory.
What surface finishes work on C17450-TH04?
Readily tin-, nickel-, silver- or gold-plated for contact surfaces; solders and brazes well, takes a bright polish, and no anodizing applies.
Can C17450-TH04 be formed, bent or molded?
Stamp and bend in the mill-hardened temper chosen for the bend radius (TM00/TM02 for tight bends); alternatively form in TB00 and age 2–3 h at ~455–480 °C, allowing for slight growth.
What is the maximum service temperature of C17450-TH04?
C17450-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 C17450-TM04 and C17450-TB00?
TM04 is the default condition — the standard stocked strip temper: best all-round mix of spring force, conductivity and bendability for high-current contacts. TB00: softest condition for deep forming or heavy machining before customer-performed age hardening. Yield strength is 600 MPa in TM04 versus 170 MPa in TB00.
Sources
- ASTM B441 — Copper-Cobalt-Beryllium and Copper-Nickel-Beryllium Rod and Bar — ASTM International (2021)
- ASTM B768 — Copper-Beryllium Alloy Strip (low-beryllium grades) — ASTM International (2019)
- CDA/UNS Alloy Datasheet C17450 — Copper Development Association (copper.org) (2023)
- High-conductivity copper beryllium strip (mill-hardened tempers) technical data — Materion / NGK Metals (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.