Copper Alloy C43500-H04
Supply condition
UNS C43500
H04 = full hard
Full-hard strip for flat springs, contacts and stamped parts requiring high yield strength and only gentle forming.
Values for the H04 condition
Other C43500 tempers and conditions
C43500 is listed in 8 conditions; see the grade overview at C43500.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.035 mm grain size | Softest commercial temper — pick for deep drawing, tube bending and severe forming of bellows/Bourdon blanks. | 110 | 315 | 50 | 55 HB | 28 % IACS |
OS025Default Annealed to 0.025 mm grain size | Standard stocked soft temper: fine grain gives a smooth drawn surface (orange-peel free) with still-excellent formability. | 125 | 330 | 46 | 60 HB | 28 % IACS |
Quarter hard | Light cold work for parts needing extra stiffness while retaining moderate bend formability. | 275 | 380 | 25 | 95 HB | 27.5 % IACS |
Hard drawn | Standard as-drawn tube temper for Bourdon tubes, gauge and instrument tubing needing elastic response with some bendability. | 310 | 415 | 20 | 115 HB | — |
Half hard | Best strength/formability compromise for springy clips, ferrules and gauge parts that still need 90° bends. | 345 | 420 | 13 | 120 HB | — |
H04This page Full hard | Full-hard strip for flat springs, contacts and stamped parts requiring high yield strength and only gentle forming. | 450 | 505 | 5 | 145 HB | — |
Extra hard | Choose when higher spring rate than H04 is needed and forming is limited to flat blanking. | 505 | 560 | 4 | 160 HB | 27 % IACS |
Spring hard | Maximum-strength strip temper for flat springs and diaphragms; essentially no cold forming capability. | 540 | 605 | 3 | 172 HB | 27 % IACS |
What is C43500-H04?
C43500-H04 is C43500 supplied in the H04 condition — full-hard strip for flat springs, contacts and stamped parts requiring high yield strength and only gentle forming. C43500-H04 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 86% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 110 GPa (16 Msi). C43500-H04 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 899°C (1,650 °F). OS025 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- High strength — 450 MPa (65.3 ksi), better than 86% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Limited ductility — 5%, worse than 93% of copper alloy grades
C43500-H04 properties
Typical room-temperature values for C43500-H04; 11 are specific to this condition. Other listed values are C43500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C43500-H04 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 899°C (1,650 °F).
Mechanical12
C43500-H04 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 86% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C43500-H04 is rated for continuous service to 150°C (302 °F). It conducts heat at 116 W/m·K (67 BTU/hr·ft·°F), better than 64% of copper alloy grades. Thermal expansion is 20.3 µm/m·K (11.3 µin/in·°F).
Electrical3
C43500-H04 conducts electricity at 28 % IACS, better than 69% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C43500-H04 takes about 55 MJ of energy and emits 3.5 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
C43500-H04's machinability is fair (38/100, better than 55% of copper alloy grades); weldability fair (40/100); formability fair (38/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C43500-H04
Is C43500 easy to machine?
Machinability ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, generous coolant and chip breakers.
Can C43500 be welded?
Solders and brazes excellently (best joining route); resistance and oxyacetylene welding fair, arc welding not recommended due to zinc fuming and porosity.
Can C43500 be formed, bent or molded?
Excellent cold formability in OS tempers — deep drawing, tube drawing and bending; stress-relieve at 250–300 °C after heavy forming to avoid season cracking.
What surface finishes work on C43500?
Not anodizable; polishes to a bright yellow-gold finish, accepts nickel/chrome/tin plating and clear lacquer, or can be chemically patinated.
C43500 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 | 79 – 83 | 81 |
| Sn | 0.6 – 1.2 | 0.9 |
| Pb | ≤ 0.1 | — |
| Fe | ≤ 0.05 | — |
| Znremainder, nominally ~18 % | balance | — |
C43500-H04 — frequently asked
What is C43500-H04 used for?
C43500-H04 is typically used for marine hardware, plumbing fittings and electrical hardware. In short: most formable tin brass; higher tin for corrosion resistance; deep-draw and tube grade.
What is the yield strength of C43500-H04?
C43500-H04 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 86% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C43500-H04 easy to machine?
Not especially — machinability is rated fair (38/100, better than 55% of copper alloy grades). Machinability ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, generous coolant and chip breakers.
Can C43500-H04 be welded?
With care — weldability is rated fair (40/100). Solders and brazes excellently (best joining route); resistance and oxyacetylene welding fair, arc welding not recommended due to zinc fuming and porosity.
What surface finishes work on C43500-H04?
Not anodizable; polishes to a bright yellow-gold finish, accepts nickel/chrome/tin plating and clear lacquer, or can be chemically patinated.
Can C43500-H04 be formed, bent or molded?
Excellent cold formability in OS tempers — deep drawing, tube drawing and bending; stress-relieve at 250–300 °C after heavy forming to avoid season cracking.
What is the maximum service temperature of C43500-H04?
C43500-H04 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 C43500-OS025 and C43500-H08?
OS025 is the default condition — standard stocked soft temper: fine grain gives a smooth drawn surface (orange-peel free) with still-excellent formability. H08: maximum-strength strip temper for flat springs and diaphragms; essentially no cold forming capability. Yield strength is 125 MPa in OS025 versus 540 MPa in H08.
Sources
- ASTM B135 / B587 — Seamless Brass Tube and Welded Brass Tube — ASTM International (2019)
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- CDA Alloy Database, C43500 tin brass — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- GB/T 26303 / GB/T 1527 (2017)
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.