Copper Alloy C42600-H08
Supply condition
UNS C42600
H08 = spring hard
Spring temper for stamped contact springs and washers needing high elastic limit and good relaxation resistance.
Values for the H08 condition
Other C42600 tempers and conditions
C42600 is listed in 7 conditions; see the grade overview at C42600.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.015 mm grain size | Softest stocked strip temper — pick for deep-drawn or severely bent parts that will be stress-relieved or work-hardened in the press. | 130 | 350 | 45 | 80 HB | 32 % IACS |
Quarter hard | Light cold work for parts needing moderate strength with still-generous 90° bend capability across grain. | 300 | 400 | 25 | 110 HB | 31 % IACS |
H02Default Half hard | The general-purpose stamping temper — best balance of spring force and formability for terminals and clips. | 395 | 450 | 12 | 130 HB | 31 % IACS |
Full hard | Standard connector-contact temper where higher contact force is needed and bends are gentle or with-grain. | 465 | 510 | 6 | 150 HB | 30 % IACS |
Extra hard | Choose when higher yield and stiffness are required and forming is limited to shallow with-grain bends. | 510 | 550 | 4 | 165 HB | 30 % IACS |
H08This page Spring hard | Spring temper for stamped contact springs and washers needing high elastic limit and good relaxation resistance. | 545 | 585 | 3 | 175 HB | 30 % IACS |
Extra spring hard | Maximum-strength strip for flat springs and high-force contacts; forming must be with-grain with generous radii. | 580 | 620 | 2 | 185 HB | 29 % IACS |
What is C42600-H08?
C42600-H08 is C42600 supplied in the H08 condition — spring temper for stamped contact springs and washers needing high elastic limit and good relaxation resistance. C42600-H08 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 92% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 110 GPa (16 Msi). C42600-H08 has a density of 8.78 g/cm³ (0.317 lb/in³), heavier than 53% of copper alloy grades. It melts at 940°C (1,724 °F). H02 is the default condition FabDigit quotes; H08 is available on request or by drawing note.
Advantages
- High strength — 545 MPa (79 ksi), better than 92% of copper alloy grades
Limitations
- Limited service temperature — 125°C (257 °F), worse than 100% of copper alloy grades
- Limited ductility — 3%, worse than 97% of copper alloy grades
C42600-H08 properties
Typical room-temperature values for C42600-H08; 12 are specific to this condition. Other listed values are C42600 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C42600-H08 has a density of 8.78 g/cm³ (0.317 lb/in³), heavier than 53% of copper alloy grades. It melts at 940°C (1,724 °F).
Mechanical12
C42600-H08 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 92% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C42600-H08 is rated for continuous service to 125°C (257 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), better than 66% of copper alloy grades. Thermal expansion is 20.2 µm/m·K (11.2 µin/in·°F).
Electrical3
C42600-H08 conducts electricity at 30 % IACS, better than 71% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C42600-H08 takes about 60 MJ of energy and emits 4 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C42600-H08's machinability is fair (42/100, better than 59% of copper alloy grades); weldability fair (40/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C42600-H08
Is C42600 easy to machine?
Machinability ≈30% of free-cutting brass — gummy chips, use sharp positive-rake tools, high speed and good lubrication; blanking/stamping is the preferred route.
Can C42600 be welded?
Excellent soldering and brazing; resistance welding fair; fusion arc welding is rarely used because zinc fumes and porosity degrade the joint.
Can C42600 be formed, bent or molded?
Alpha single-phase alloy with excellent cold formability in OS015/H01; for H04 and harder, bend with-grain with radius ≥1–2 t and expect springback typical of tin brass.
What surface finishes work on C42600?
Takes bright polish and readily accepts tin, nickel, silver or gold electroplating for contacts; not anodizable — use lacquer or plating for tarnish resistance, and stress-relieve (≈200–260 °C) formed parts to avoid ammonia SCC.
C42600 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 |
|---|---|---|
| Cucopper plus silver | 87 – 90 | 88.5 |
| Snlow-tin registered range; confirm against current CDA/ASTM B591 registration for the specific mill | 0.3 – 1.2 | 0.9 |
| Pdeoxidizer, improves stress relaxation | 0.02 – 0.35 | 0.05 |
| Feimpurity limit | ≤ 0.05 | — |
| Pbimpurity limit | ≤ 0.05 | — |
| Znremainder, ≈10–12% | balance | — |
C42600-H08 — frequently asked
What is C42600-H08 used for?
C42600-H08 is typically used for stamped springs, connectors and terminals. In short: formable tin-brass spring strip; 31% IACS conductivity; stamping grade, not machining.
What is the yield strength of C42600-H08?
C42600-H08 has a typical yield strength of 545 MPa (79 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 92% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C42600-H08 easy to machine?
Not especially — machinability is rated fair (42/100, better than 59% of copper alloy grades). Machinability ≈30% of free-cutting brass — gummy chips, use sharp positive-rake tools, high speed and good lubrication; blanking/stamping is the preferred route.
Can C42600-H08 be welded?
With care — weldability is rated fair (40/100). Excellent soldering and brazing; resistance welding fair; fusion arc welding is rarely used because zinc fumes and porosity degrade the joint.
What surface finishes work on C42600-H08?
Takes bright polish and readily accepts tin, nickel, silver or gold electroplating for contacts; not anodizable — use lacquer or plating for tarnish resistance, and stress-relieve (≈200–260 °C) formed parts to avoid ammonia SCC.
Can C42600-H08 be formed, bent or molded?
Alpha single-phase alloy with excellent cold formability in OS015/H01; for H04 and harder, bend with-grain with radius ≥1–2 t and expect springback typical of tin brass.
What is the maximum service temperature of C42600-H08?
C42600-H08 is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C42600-H02 and C42600-OS015?
H02 is the default condition — the general-purpose stamping temper — best balance of spring force and formability for terminals and clips. OS015: softest stocked strip temper — pick for deep-drawn or severely bent parts that will be stress-relieved or work-hardened in the press. Yield strength is 395 MPa in H02 versus 130 MPa in OS015.
Sources
- ASTM B591 — Copper-Zinc-Tin Alloy Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- CDA Alloy Database, tin brass group (C42200/C42500/C42600) — Copper Development Association (2024)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASTM B601 — Temper Designations for Copper and Copper Alloys — ASTM International (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.