Copper Alloy C19010-TM04
Precip hard · default condition
UNS C19010 · EN CW109C, CuNi2Si
TM04 = mill hardened, full hard
The workhorse condition: age hardened at the mill for full-hard-class strength with usable formability and 55–65 % IACS.
Values for the TM04 condition
Other C19010 tempers and conditions
C19010 is listed in 13 conditions; see the grade overview at C19010.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for deep-drawn or severely formed parts that will be precipitation aged by the user after forming. | 130 | 310 | 35 | 40 HRB | 45 % IACS |
Quarter hard | Lowest cold-rolled temper: pick when tight bends and forming dominate over spring force. | 340 | 400 | 13 | 62 HRB | 58 % IACS |
Half hard | Balanced strength/formability cold-rolled temper for stamped terminals with moderate bends. | 400 | 440 | 9 | 70 HRB | 57 % IACS |
Mill hardened, half hard | Mill-hardened level for parts needing good bend formability plus better stress relaxation than plain cold work. | 400 | 450 | 13 | 68 HRB | 61 % IACS |
Three-quarter hard | Use when H02 lacks contact force but full-hard bend performance is still needed. | 435 | 470 | 7 | 74 HRB | 56 % IACS |
Mill hardened, intermediate strength | Pick for stamped connector contacts needing 90° bends in both directions with H03-class strength. | 445 | 490 | 11 | 73 HRB | 60 % IACS |
Full hard | Standard hard cold-rolled strip for flat stamped conductors and lead frames with simple bends. | 470 | 500 | 5 | 78 HRB | 55 % IACS |
TM04DefaultThis page Mill hardened, full hard | The workhorse condition: age hardened at the mill for full-hard-class strength with usable formability and 55–65 % IACS. | 480 | 520 | 8 | 77 HRB | 60 % IACS |
Extra hard | Higher cold-work level for straight stamped springs where bending is minimal. | 515 | 540 | 3.5 | 82 HRB | 55 % IACS |
Mill hardened, extra hard | Higher mill-hardened level for higher contact normal force and better relaxation resistance at 150–200 °C. | 535 | 570 | 6 | 82 HRB | 58 % IACS |
Spring hard | Spring temper strip for high contact-force clips accepting limited bend formability. | 550 | 570 | 2.5 | 85 HRB | 54 % IACS |
Extra spring hard | Maximum cold-rolled strength for flat springs with essentially no forming after rolling. | 580 | 600 | 2 | 88 HRB | 54 % IACS |
Mill hardened, spring hard | Top mill-hardened level: strongest spring performance of C19010 while keeping >55 % IACS. | 580 | 610 | 4 | 86 HRB | 57 % IACS |
What is C19010-TM04?
C19010-TM04 is C19010 in the TM04 condition — the workhorse condition: age hardened at the mill for full-hard-class strength with usable formability and 55–65 % IACS. C19010-TM04 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 131 GPa (19 Msi). C19010-TM04 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 1,075°C (1,967 °F).
Advantages
- 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
- Conducts heat well — 230 W/m·K (132.9 BTU/hr·ft·°F), better than 81% of copper alloy grades
- High electrical conductivity — 60 % IACS, better than 81% of copper alloy grades
Limitations
- Limited ductility — 8%, worse than 83% of copper alloy grades
C19010-TM04 properties
Typical room-temperature values for C19010-TM04; 12 are specific to this condition. Other listed values are C19010 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C19010-TM04 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 1,075°C (1,967 °F).
Mechanical11
C19010-TM04 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 131 GPa (19 Msi).
Thermal6
C19010-TM04 is rated for continuous service to 200°C (392 °F). It conducts heat at 230 W/m·K (132.9 BTU/hr·ft·°F), better than 81% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C19010-TM04 conducts electricity at 60 % IACS, better than 81% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C19010-TM04 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 30%.
Manufacturability7
C19010-TM04's machinability is fair (40/100, better than 57% of copper alloy grades); weldability fair (45/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C19010-TM04
Is C19010 easy to machine?
Machines like a tough, gummy copper alloy — sharp positive-rake carbide, high speed, generous coolant; expect burrs and plan for deburring on stamped edges.
Can C19010 be welded?
Resistance, laser and ultrasonic joining are routine; fusion arc welding locally dissolves the Ni-Si precipitates and softens the HAZ, so avoid it on spring sections.
Can C19010 be formed, bent or molded?
Stamp and form in mill-hardened tempers (TM03–TM06) for the best bend-versus-strength trade-off; align tight bends good-way when possible and allow more springback than for brass.
What surface finishes work on C19010?
Not anodizable; standard finishes are matte/bright tin, nickel underplate plus gold or silver for contacts — solderability is excellent, and bare surfaces tarnish so store dry.
C19010 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 |
|---|---|---|
| Niprimary precipitate former with Si | 0.8 – 1.8 | 1.1 |
| Si | 0.15 – 0.35 | 0.22 |
| P | 0.01 – 0.04 | 0.03 |
| Pbimpurity limit | ≤ 0.02 | — |
| CuCu + named elements 99.8 % min; Cu 98.7 % min | balance | — |
C19010-TM04 — frequently asked
What is C19010-TM04 used for?
C19010-TM04 is typically used for electrical/electronic connectors, lead frames and high-strength contacts. In short: 60% IACS spring copper; mill-hardened connector strip; beryllium-free contact alloy.
What is the yield strength of C19010-TM04?
C19010-TM04 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 88% of copper alloy grades. Strength varies by condition: see the 13 listed tempers.
Is C19010-TM04 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machines like a tough, gummy copper alloy — sharp positive-rake carbide, high speed, generous coolant; expect burrs and plan for deburring on stamped edges.
Can C19010-TM04 be welded?
With care — weldability is rated fair (45/100). Resistance, laser and ultrasonic joining are routine; fusion arc welding locally dissolves the Ni-Si precipitates and softens the HAZ, so avoid it on spring sections.
What surface finishes work on C19010-TM04?
Not anodizable; standard finishes are matte/bright tin, nickel underplate plus gold or silver for contacts — solderability is excellent, and bare surfaces tarnish so store dry.
Can C19010-TM04 be formed, bent or molded?
Stamp and form in mill-hardened tempers (TM03–TM06) for the best bend-versus-strength trade-off; align tight bends good-way when possible and allow more springback than for brass.
What is the maximum service temperature of C19010-TM04?
C19010-TM04 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 C19010-TM04 and C19010-O60?
TM04 is the default condition — the workhorse condition: age hardened at the mill for full-hard-class strength with usable formability and 55–65 % IACS. O60: choose for deep-drawn or severely formed parts that will be precipitation aged by the user after forming. Yield strength is 480 MPa in TM04 versus 130 MPa in O60.
Sources
- ASTM B747/B747M — Copper Alloy Strip for Use in Manufacture of Electrical Connectors or Spring Contacts — ASTM International (2021)
- ASTM B888/B888M — Copper Alloy Strip for Automotive Electrical Connectors — ASTM International (2020)
- CDA/UNS alloy registration data for C19010 — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- High-performance Cu-Ni-Si connector strip datasheets (Wieland / Materion / KME class products) — various producers (2023)
- EN 1654 / CW109C (CuNi2Si) strip for springs and connectors — CEN (2019)
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.