Copper Alloy C27400-H03
Supply condition
UNS C27400 · EN CW508L, CuZn37
H03 = three-quarter hard
Pick for flat parts and light forming where higher yield strength is required than H02.
Values for the H03 condition
Other C27400 tempers and conditions
C27400 is listed in 8 conditions; see the grade overview at C27400.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Pick for deep drawing, severe bending and spinning where maximum ductility is needed. | 125 | 340 | 55 | 60 HB | 28 % IACS |
Quarter hard | Pick when moderate strength must be combined with substantial forming or bending. | 270 | 385 | 43 | 95 HB | — |
H02Default Half hard | The general-purpose stock temper: good strength with enough ductility for stamping and 90° bends. | 340 | 425 | 23 | 125 HB | — |
H03This page Three-quarter hard | Pick for flat parts and light forming where higher yield strength is required than H02. | 395 | 470 | 12 | 145 HB | — |
Full hard | Pick for flat blanked/pierced parts, shims and contacts needing high strength and stiffness in service. | 425 | 510 | 8 | 155 HB | — |
Extra hard | Pick for thin flat springs, clips and wear surfaces where forming is limited to gentle radii. | 455 | 570 | 5 | 175 HB | — |
Spring hard | Pick for spring contacts, washers and detents requiring high elastic limit; form only across the rolling direction. | 490 | 620 | 3 | 185 HB | — |
Extra spring hard | Pick for the highest strength/elastic limit available in this alloy; essentially flat-form only. | 510 | 650 | 3 | 195 HB | — |
What is C27400-H03?
C27400-H03 is C27400 supplied in the H03 condition — pick for flat parts and light forming where higher yield strength is required than H02. C27400-H03 has a yield strength of 395 MPa (57.3 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 79% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 105 GPa (15.2 Msi). C27400-H03 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 70% of copper alloy grades. It melts at 900°C (1,652 °F). H02 is the default condition FabDigit quotes; H03 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- High strength — 395 MPa (57.3 ksi), better than 79% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
C27400-H03 properties
Typical room-temperature values for C27400-H03; 11 are specific to this condition. Other listed values are C27400 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C27400-H03 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 70% of copper alloy grades. It melts at 900°C (1,652 °F).
Mechanical12
C27400-H03 has a yield strength of 395 MPa (57.3 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 79% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C27400-H03 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 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
C27400-H03 conducts electricity at 27 % IACS, better than 67% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C27400-H03 takes about 55 MJ of energy and emits 3.8 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 45%.
Manufacturability7
C27400-H03's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability fair (45/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C27400-H03
Is C27400 easy to machine?
Machinable but chip-forming (rating ~30% of free-cutting brass) — use sharp positive-rake tools, high speed and light feed; choose C36000 if turning volume matters.
Can C27400 be welded?
Resistance and brazing/soldering are excellent; fusion welding is only fair because zinc volatilises — use low-heat processes with ventilation and Si-bronze filler.
Can C27400 be formed, bent or molded?
Excellent cold formability in O60/H01 for deep drawing and bending; harder tempers need generous bend radii and stress-relief (250–300 °C) to avoid season cracking.
What surface finishes work on C27400?
Polishes to a bright yellow finish, takes Ni/Cr/Ag electroplating and chemical patinas readily; lacquer or clear-coat to prevent tarnish (not anodizable).
C27400 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 silver | 61 – 64 | 63 |
| Pbsmall intentional lead addition | 0.05 – 0.15 | 0.1 |
| Fe | ≤ 0.05 | — |
| Znremainder, ~36–39% | balance | — |
C27400-H03 — frequently asked
What is C27400-H03 used for?
C27400-H03 is typically used for hardware, stampings, screws and fittings. In short: balanced strength and formability; general-purpose yellow brass; cold-workable to H10.
What is the yield strength of C27400-H03?
C27400-H03 has a typical yield strength of 395 MPa (57.3 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 79% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C27400-H03 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Machinable but chip-forming (rating ~30% of free-cutting brass) — use sharp positive-rake tools, high speed and light feed; choose C36000 if turning volume matters.
Can C27400-H03 be welded?
With care — weldability is rated fair (45/100). Resistance and brazing/soldering are excellent; fusion welding is only fair because zinc volatilises — use low-heat processes with ventilation and Si-bronze filler.
What surface finishes work on C27400-H03?
Polishes to a bright yellow finish, takes Ni/Cr/Ag electroplating and chemical patinas readily; lacquer or clear-coat to prevent tarnish (not anodizable).
Can C27400-H03 be formed, bent or molded?
Excellent cold formability in O60/H01 for deep drawing and bending; harder tempers need generous bend radii and stress-relief (250–300 °C) to avoid season cracking.
What is the maximum service temperature of C27400-H03?
C27400-H03 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 C27400-H02 and C27400-O60?
H02 is the default condition — the general-purpose stock temper: good strength with enough ductility for stamping and 90° bends. O60: pick for deep drawing, severe bending and spinning where maximum ductility is needed. Yield strength is 340 MPa in H02 versus 125 MPa in O60.
Sources
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- CDA Alloy Datasheet C27400 (Yellow Brass) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- EN 1652 / CW508L CuZn37 wrought copper products — CEN (1997)
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.