Copper Alloy C43000-H08
Supply condition
UNS C43000
H08 = spring hard
Pick for flat springs, clips and connector contacts needing high elastic limit with corrosion resistance.
Values for the H08 condition
Other C43000 tempers and conditions
C43000 is listed in 8 conditions; see the grade overview at C43000.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.035 mm grain size | Pick for deep drawing, severe bending and forming before any final stress-relief. | 125 | 340 | 48 | 40 HRB | 26 % IACS |
Quarter hard | Pick when moderate strength must be combined with continued bending and light drawing. | 310 | 400 | 32 | 62 HRB | 25 % IACS |
H02Default Half hard | The general-purpose stock temper: balanced strength and formability for marine and electrical hardware. | 385 | 455 | 20 | 72 HRB | 25 % IACS |
Three-quarter hard | Pick for higher-strength stamped parts needing only gentle bends across the grain. | 430 | 495 | 12 | 78 HRB | 25 % IACS |
Full hard | Pick for flat, high-strength contacts and hardware with minimal forming after blanking. | 470 | 540 | 7 | 82 HRB | 24 % IACS |
Extra hard | Pick when yield strength and stiffness of thin strip matter more than any bending. | 540 | 605 | 4 | 88 HRB | 24 % IACS |
H08This page Spring hard | Pick for flat springs, clips and connector contacts needing high elastic limit with corrosion resistance. | 585 | 650 | 3 | 91 HRB | 24 % IACS |
Extra spring hard | Pick for the highest strength thin strip; essentially flat-form only, bends must follow the grain. | 620 | 680 | 2 | 93 HRB | 24 % IACS |
What is C43000-H08?
C43000-H08 is C43000 supplied in the H08 condition — pick for flat springs, clips and connector contacts needing high elastic limit with corrosion resistance. C43000-H08 has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 93% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 110 GPa (16 Msi). C43000-H08 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 900°C (1,652 °F). H02 is the default condition FabDigit quotes; H08 is available on request or by drawing note.
Advantages
- High strength — 585 MPa (84.8 ksi), better than 93% of copper alloy grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 100% of copper alloy grades
- Limited ductility — 3%, worse than 97% of copper alloy grades
C43000-H08 properties
Typical room-temperature values for C43000-H08; 11 are specific to this condition. Other listed values are C43000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C43000-H08 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 900°C (1,652 °F).
Mechanical12
C43000-H08 has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 93% of copper alloy grades. Elongation at break is 3% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C43000-H08 is rated for continuous service to 120°C (248 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 58% of copper alloy grades. Thermal expansion is 19.1 µm/m·K (10.6 µin/in·°F).
Electrical3
C43000-H08 conducts electricity at 24 % IACS, better than 57% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C43000-H08 takes about 60 MJ of energy and emits 3.7 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C43000-H08's machinability is fair (40/100, better than 57% of copper alloy grades); weldability good (55/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C43000-H08
Is C43000 easy to machine?
Unleaded tin brass machines at roughly 30 % of free-cutting C36000 — expect stringy chips; use sharp positive-rake tools, high speed and good lubrication, or specify a leaded grade if turning volume is high.
Can C43000 be welded?
Resistance and brazing/soldering are excellent; fusion welding (GTAW with Cu-Sn or Si-bronze filler) is fair with zinc-fume extraction and low heat input.
Can C43000 be formed, bent or molded?
Excellent cold formability in OS035/H01; drawing, bending and coining are routine, with interanneal at 425–600 °C and stress-relief at 250–300 °C to avoid season cracking.
What surface finishes work on C43000?
Takes a bright mechanical or electropolish, plus tin, nickel, silver or gold plating for contacts; not anodizable — use lacquer or patina for architectural/marine trim.
C43000 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 |
|---|---|---|
| Cuincludes Ag | 84 – 87 | 85.5 |
| Sn | 1.7 – 2.7 | 2.2 |
| Pb | ≤ 0.05 | — |
| Fe | ≤ 0.05 | — |
| Znremainder, nominally ~12–13 % | balance | — |
C43000-H08 — frequently asked
What is C43000-H08 used for?
C43000-H08 is typically used for marine hardware, electrical parts and fasteners. In short: corrosion-resistant tin brass; 20% elongation at strength; unleaded, slow to machine.
What is the yield strength of C43000-H08?
C43000-H08 has a typical yield strength of 585 MPa (84.8 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 93% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C43000-H08 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Unleaded tin brass machines at roughly 30 % of free-cutting C36000 — expect stringy chips; use sharp positive-rake tools, high speed and good lubrication, or specify a leaded grade if turning volume is high.
Can C43000-H08 be welded?
Yes — weldability is rated good (55/100). Resistance and brazing/soldering are excellent; fusion welding (GTAW with Cu-Sn or Si-bronze filler) is fair with zinc-fume extraction and low heat input.
What surface finishes work on C43000-H08?
Takes a bright mechanical or electropolish, plus tin, nickel, silver or gold plating for contacts; not anodizable — use lacquer or patina for architectural/marine trim.
Can C43000-H08 be formed, bent or molded?
Excellent cold formability in OS035/H01; drawing, bending and coining are routine, with interanneal at 425–600 °C and stress-relief at 250–300 °C to avoid season cracking.
What is the maximum service temperature of C43000-H08?
C43000-H08 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C43000-H02 and C43000-OS035?
H02 is the default condition — the general-purpose stock temper: balanced strength and formability for marine and electrical hardware. OS035: pick for deep drawing, severe bending and forming before any final stress-relief. Yield strength is 385 MPa in H02 versus 125 MPa in OS035.
Sources
- CDA Alloy Datasheet C43000 (Tin Brass) — Copper Development Association (2023)
- ASTM B591 — Copper-Zinc-Tin Alloy Plate, Sheet, Strip and Rolled Bar — ASTM International (2022)
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- 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.