Copper Alloy C79200-H04
Supply condition · default condition
UNS C79200 · EN CW404J
H04 = full hard
Default stocked temper for precision turned and stamped parts requiring maximum strength, stiffness of form and clean chip breaking.
Values for the H04 condition
Other C79200 tempers and conditions
C79200 is listed in 6 conditions; see the grade overview at C79200.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.035 mm grain size | Softest stocked condition — pick for deep drawing, bending and severe forming before final machining. | 170 | 380 | 40 | 100 HB | 9.5 % IACS |
Quarter hard | Best compromise when parts must still be bent or staked after machining but need more strength than annealed. | 310 | 450 | 25 | 130 HB | 9 % IACS |
Half hard | Common rod/strip stock for screw-machine parts needing moderate strength with some residual ductility. | 415 | 510 | 12 | 150 HB | 9 % IACS |
H04DefaultThis page Full hard | Default stocked temper for precision turned and stamped parts requiring maximum strength, stiffness of form and clean chip breaking. | 510 | 585 | 5 | 8 HRC | 9 % IACS |
Extra hard | Choose for flat springs and contacts where high yield strength matters more than bendability. | 570 | 640 | 3 | 11 HRC | 9 % IACS |
Spring hard | Highest strength strip temper for spring contacts and clips; forming limited to gentle radii along the grain. | 605 | 675 | 2 | 13 HRC | 9 % IACS |
What is C79200-H04?
C79200-H04 is C79200 supplied in the H04 condition — default stocked temper for precision turned and stamped parts requiring maximum strength, stiffness of form and clean chip breaking. C79200-H04 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 90% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 124 GPa (18 Msi). C79200-H04 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 995°C (1,823 °F).
Advantages
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- High strength — 510 MPa (74 ksi), better than 90% of copper alloy grades
- Easy to machine — 75/100, better than 80% of copper alloy grades
Limitations
- Limited ductility — 5%, worse than 93% of copper alloy grades
- Limited service temperature — 175°C (347 °F), worse than 92% of copper alloy grades
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- High embodied carbon — 4.6 kg CO₂/kg, worse than 82% of copper alloy grades
- Low electrical conductivity — 9 % IACS, worse than 78% of copper alloy grades
C79200-H04 properties
Typical room-temperature values for C79200-H04; 22 are specific to this condition. Other listed values are C79200 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C79200-H04 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 56% of copper alloy grades. It melts at 995°C (1,823 °F).
Mechanical16
C79200-H04 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 90% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C79200-H04 is rated for continuous service to 175°C (347 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C79200-H04 conducts electricity at 9 % IACS, worse than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (64/100), better than 52% of copper alloy grades.
Sustainability4
Producing a kilogram of C79200-H04 takes about 68 MJ of energy and emits 4.6 kg of CO₂ — more than 83% of copper alloy grades. Typical recycled content is 40%.
Manufacturability6
C79200-H04's machinability is very good (75/100, better than 80% of copper alloy grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C79200-H04
Is C79200 easy to machine?
Excellent free-cutting behaviour from the lead phase — short chips, high speeds, use sharp positive-rake carbide and light oil-based coolant; rating ~65% of free-cutting brass.
Can C79200 be welded?
Not suitable for fusion welding because of the lead; join by soft soldering (excellent) or low-temperature silver brazing with careful heat control.
Can C79200 be formed, bent or molded?
Cold form only in OS/H01 tempers; hot working is poor due to lead hot-shortness, and hard tempers crack on tight bends across the grain.
What surface finishes work on C79200?
Takes a bright silver-white polish and accepts nickel, chrome or silver plating readily; clear lacquer or passivation is used to slow tarnishing in humid service.
C79200 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 |
|---|---|---|
| Cu | 59 – 66.5 | 63.5 |
| Niincludes Co | 10 – 12.5 | 12 |
| Pbfree-machining addition | 0.8 – 2 | 1.5 |
| Fe | ≤ 0.25 | — |
| Mn | ≤ 0.5 | — |
| Znremainder, nominally ~23% | balance | — |
C79200-H04 — frequently asked
What is C79200-H04 used for?
C79200-H04 is typically used for precision turned components, hardware, instrument fittings and decorative screws. In short: free-machining nickel silver; highest strength in family; not for fusion welding.
What is the yield strength of C79200-H04?
C79200-H04 has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 90% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C79200-H04 easy to machine?
Yes — machinability is rated very good (75/100, better than 80% of copper alloy grades). Excellent free-cutting behaviour from the lead phase — short chips, high speeds, use sharp positive-rake carbide and light oil-based coolant; rating ~65% of free-cutting brass.
Can C79200-H04 be welded?
Not readily — weldability is rated poor (20/100). Not suitable for fusion welding because of the lead; join by soft soldering (excellent) or low-temperature silver brazing with careful heat control.
What surface finishes work on C79200-H04?
Takes a bright silver-white polish and accepts nickel, chrome or silver plating readily; clear lacquer or passivation is used to slow tarnishing in humid service.
Can C79200-H04 be formed, bent or molded?
Cold form only in OS/H01 tempers; hot working is poor due to lead hot-shortness, and hard tempers crack on tight bends across the grain.
What is the maximum service temperature of C79200-H04?
C79200-H04 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C79200-H04 and C79200-OS035?
H04 is the default condition — default stocked temper for precision turned and stamped parts requiring maximum strength, stiffness of form and clean chip breaking. OS035: softest stocked condition — pick for deep drawing, bending and severe forming before final machining. Yield strength is 510 MPa in H04 versus 170 MPa in OS035.
Sources
- ASTM B122/B122M — Copper-Nickel-Zinc (Nickel Silver) Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- ASTM B151/B151M — Copper-Nickel-Zinc and Copper-Nickel Rod and Bar — ASTM International (2021)
- EN 12163/12164 — CuNi12Zn24Pb1 (CW404J) — CEN (2016)
- CDA/UNS C79200 alloy datasheet — Copper Development Association (2023)
- 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.