Copper Alloy C19000-HR04
Temper
UNS C19000 · EN CW108C, CuNi1P
HR04 = full hard, cold rolled and stress relieved
High-strength strip for flat springs and stamped contacts where bends are gentle and mostly with the grain.
Values for the HR04 condition
Other C19000 tempers and conditions
C19000 is listed in 7 conditions; see the grade overview at C19000.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated | Softest condition for deep drawing or severe forming before ageing; lowest strength and lowest conductivity because Ni and P are still in solution. | 90 | 275 | 40 | 35 HRB | 30 % IACS |
Solution heat treated and precipitation hardened | Form parts soft, then age at ~450–500 °C to precipitate Ni₃P — good strength with the alloy's highest conductivity and full ductility retention. | 310 | 400 | 18 | 68 HRB | 48 % IACS |
Quarter hard, cold rolled and stress relieved | Light cold work plus stress relief; choose when moderate strength must be combined with substantial bending formability. | 380 | 425 | 13 | 72 HRB | 45 % IACS |
HR02Default Half hard, cold rolled and stress relieved | The workhorse strip temper: balanced strength, formability and conductivity for connectors, contact springs and lead frames. | 448 | 483 | 8 | 78 HRB | 43 % IACS |
HR04This page Full hard, cold rolled and stress relieved | High-strength strip for flat springs and stamped contacts where bends are gentle and mostly with the grain. | 517 | 552 | 5 | 84 HRB | 42 % IACS |
Spring temper, cold rolled and stress relieved | Spring temper for relay blades and contact fingers needing high elastic limit and low stress relaxation at moderate temperature. | 586 | 620 | 3 | 89 HRB | 41 % IACS |
Extra spring temper, cold rolled and stress relieved | Maximum strength temper for thin, flat, lightly formed springs; very limited bend formability, form only with generous radii along the grain. | 640 | 670 | 2 | 93 HRB | 40 % IACS |
What is C19000-HR04?
C19000-HR04 is C19000 in the HR04 temper — high-strength strip for flat springs and stamped contacts where bends are gentle and mostly with the grain. C19000-HR04 has a yield strength of 517 MPa (75 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 125 GPa (18.1 Msi). C19000-HR04 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,075°C (1,967 °F). HR02 is the default condition FabDigit quotes; HR04 is available on request or by drawing note.
Advantages
- High strength — 517 MPa (75 ksi), better than 91% of copper alloy grades
- High electrical conductivity — 42 % IACS, better than 75% of copper alloy grades
Limitations
- Limited ductility — 5%, worse than 93% of copper alloy grades
C19000-HR04 properties
Typical room-temperature values for C19000-HR04; 13 are specific to this condition. Other listed values are C19000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C19000-HR04 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,075°C (1,967 °F).
Mechanical11
C19000-HR04 has a yield strength of 517 MPa (75 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
C19000-HR04 is rated for continuous service to 180°C (356 °F). It conducts heat at 178 W/m·K (102.8 BTU/hr·ft·°F), better than 74% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C19000-HR04 conducts electricity at 42 % IACS, better than 75% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C19000-HR04 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C19000-HR04's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability good (55/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C19000-HR04
Is C19000 easy to machine?
Gummy and low-rated (~20 % of free-cutting brass); use sharp positive-rake tools, high speed, light feeds and generous coolant, or buy near-net stamped strip.
Can C19000 be welded?
Solders and brazes very well; GTAW/GMAW possible with Cu-Ni or deoxidised-Cu filler but the heat-affected zone over-ages and loses strength — resistance welding is poor.
Can C19000 be formed, bent or molded?
Form in TB00/TF00 or the lower HR tempers; hard tempers need bend radii ≥1–2 t with the grain and should be aged/stress-relieved after severe forming.
What surface finishes work on C19000?
Not anodisable; tin, silver, nickel or gold plating is standard for contacts, and it takes a bright mechanical polish but tarnishes without a lacquer or plated finish.
C19000 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 |
|---|---|---|
| Niforms Ni₃P precipitates on ageing | 0.9 – 1.3 | 1.1 |
| P | 0.15 – 0.35 | 0.25 |
| Zn | ≤ 0.2 | — |
| Pb | ≤ 0.05 | — |
| Fe | ≤ 0.05 | — |
| CuCu + named elements ≥ 99.5 %, Ag countable as Cu | balance | — |
C19000-HR04 — frequently asked
What is C19000-HR04 used for?
C19000-HR04 is typically used for electrical connectors, springs and contacts and relay parts. In short: age-hardening copper spring alloy; 43% IACS after aging; lower-cost precipitation copper.
What is the yield strength of C19000-HR04?
C19000-HR04 has a typical yield strength of 517 MPa (75 ksi) and a tensile strength of 552 MPa (80.1 ksi) — stronger than 91% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C19000-HR04 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Gummy and low-rated (~20 % of free-cutting brass); use sharp positive-rake tools, high speed, light feeds and generous coolant, or buy near-net stamped strip.
Can C19000-HR04 be welded?
Yes — weldability is rated good (55/100). Solders and brazes very well; GTAW/GMAW possible with Cu-Ni or deoxidised-Cu filler but the heat-affected zone over-ages and loses strength — resistance welding is poor.
What surface finishes work on C19000-HR04?
Not anodisable; tin, silver, nickel or gold plating is standard for contacts, and it takes a bright mechanical polish but tarnishes without a lacquer or plated finish.
Can C19000-HR04 be formed, bent or molded?
Form in TB00/TF00 or the lower HR tempers; hard tempers need bend radii ≥1–2 t with the grain and should be aged/stress-relieved after severe forming.
What is the maximum service temperature of C19000-HR04?
C19000-HR04 is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C19000-HR02 and C19000-TB00?
HR02 is the default condition — the workhorse strip temper: balanced strength, formability and conductivity for connectors, contact springs and lead frames. TB00: softest condition for deep drawing or severe forming before ageing; lowest strength and lowest conductivity because Ni and P are still in solution. Yield strength is 448 MPa in HR02 versus 90 MPa in TB00.
Sources
- ASTM B888/B888M — Copper Alloy Strip for Electrical Connectors — ASTM International (2020)
- EN 1654 / EN 12163 — CuNi1P (CW108C) wrought copper alloys — CEN (2019)
- CDA Alloy Database, C19000 datasheet — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.