Copper Alloy C79200-H08
Supply condition
UNS C79200 · EN CW404J
H08 = spring hard
Highest strength strip temper for spring contacts and clips; forming limited to gentle radii along the grain.
Values for the H08 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 |
H04Default 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 |
H08This page 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-H08?
C79200-H08 is C79200 supplied in the H08 condition — highest strength strip temper for spring contacts and clips; forming limited to gentle radii along the grain. C79200-H08 has a yield strength of 605 MPa (87.7 ksi) and a tensile strength of 675 MPa (97.9 ksi) — stronger than 94% of copper alloy grades. Elongation at break is 2% and the elastic modulus is 124 GPa (18 Msi). C79200-H08 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). H04 is the default condition FabDigit quotes; H08 is available on request or by drawing note.
Advantages
- High strength — 605 MPa (87.7 ksi), better than 94% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Easy to machine — 80/100, better than 86% of copper alloy grades
Limitations
- Limited ductility — 2%, worse than 98% of copper alloy grades
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Limited formability — 10/100, worse than 89% 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
C79200-H08 properties
Typical room-temperature values for C79200-H08; 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-H08 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-H08 has a yield strength of 605 MPa (87.7 ksi) and a tensile strength of 675 MPa (97.9 ksi) — stronger than 94% of copper alloy grades. Elongation at break is 2% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C79200-H08 is rated for continuous service to 150°C (302 °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-H08 conducts electricity at 9 % IACS, worse than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C79200-H08 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-H08's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (20/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C79200-H08
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-H08 — frequently asked
What is C79200-H08 used for?
C79200-H08 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-H08?
C79200-H08 has a typical yield strength of 605 MPa (87.7 ksi) and a tensile strength of 675 MPa (97.9 ksi) — stronger than 94% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C79200-H08 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% 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-H08 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-H08?
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-H08 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-H08?
C79200-H08 is rated for continuous use to about 150°C (302 °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.