Copper Alloy C27000-H04
Supply condition
UNS C27000 · ASTM B36 · EN CuZn35, CW508L · JIS C2700 · GB H65
H04 = full hard
Standard structural hard temper for flat springs, clips, terminals and stiff stamped parts with simple bends.
Values for the H04 condition
Other C27000 tempers and conditions
C27000 is listed in 9 conditions; see the grade overview at C27000.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for deep drawing, severe bending and spinning where maximum ductility is needed. | 115 | 340 | 55 | 60 HB | 27 % IACS |
As hot rolled | Low-cost mill condition for hot-extruded rod, sections and forging stock that will be machined or re-worked. | 140 | 360 | 45 | 70 HB | 27 % IACS |
Quarter hard | Light cold work for parts still needing moderate bending and forming with more stiffness than soft temper. | 275 | 395 | 43 | 105 HB | 27 % IACS |
H02Default Half hard | Default stocked temper: balanced strength and formability for hardware, stampings, fasteners and machined parts. | 340 | 430 | 23 | 125 HB | 27 % IACS |
Three-quarter hard | Use where higher yield strength is needed but shallow forming/bending across grain is still required. | 400 | 470 | 15 | 145 HB | 27 % IACS |
H04This page Full hard | Standard structural hard temper for flat springs, clips, terminals and stiff stamped parts with simple bends. | 425 | 525 | 8 | 155 HB | 26 % IACS |
Extra hard | Pick when high strength and stiffness matter and forming is limited to flat blanking or very generous bends. | 450 | 585 | 5 | 170 HB | 26 % IACS |
Spring hard | Spring temper strip for contacts, washers and light springs where elastic limit governs. | 470 | 620 | 4 | 180 HB | 26 % IACS |
Extra spring hard | Maximum cold-worked strength for flat spring strip; essentially no formability and highest SCC sensitivity — stress relieve after forming. | 490 | 650 | 3 | 188 HB | 26 % IACS |
What is C27000-H04?
C27000-H04 is C27000 supplied in the H04 condition — standard structural hard temper for flat springs, clips, terminals and stiff stamped parts with simple bends. C27000-H04 has a yield strength of 425 MPa (61.6 ksi) and a tensile strength of 525 MPa (76.1 ksi) — stronger than 83% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 105 GPa (15.2 Msi). C27000-H04 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 905°C (1,661 °F). H02 is the default condition FabDigit quotes; H04 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 — 425 MPa (61.6 ksi), better than 83% of copper alloy grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 100% of copper alloy grades
- Needs corrosion protection — 50/100, worse than 95% of copper alloy grades
- Limited ductility — 8%, worse than 83% of copper alloy grades
C27000-H04 properties
Typical room-temperature values for C27000-H04; 14 are specific to this condition. Other listed values are C27000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C27000-H04 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 905°C (1,661 °F).
Mechanical12
C27000-H04 has a yield strength of 425 MPa (61.6 ksi) and a tensile strength of 525 MPa (76.1 ksi) — stronger than 83% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C27000-H04 is rated for continuous service to 120°C (248 °F). It conducts heat at 121 W/m·K (69.9 BTU/hr·ft·°F), better than 68% of copper alloy grades. Thermal expansion is 20.3 µm/m·K (11.3 µin/in·°F).
Electrical3
C27000-H04 conducts electricity at 26 % IACS, better than 63% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 95% of copper alloy grades.
Sustainability4
Producing a kilogram of C27000-H04 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 50%.
Manufacturability8
C27000-H04's machinability is fair (40/100, better than 57% of copper alloy grades); weldability fair (40/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C27000-H04
Is C27000 easy to machine?
Machinability ~30 % of free-cutting C36000 — gummy, long chips; use sharp positive-rake tools, high speed, light feed and good lubrication, or specify C37700/C36000 for high-volume turning.
Can C27000 be welded?
Best joined by soft soldering or silver brazing; resistance and GTAW welding are possible but zinc volatilises — use good fume extraction, low heat input and Si-bronze filler.
Can C27000 be formed, bent or molded?
Excellent cold formability in O60/H01 for deep drawing, spinning and bending; interstage anneal at 425–600 °C and stress relieve at 260–300 °C after severe forming to avoid season cracking.
What surface finishes work on C27000?
Polishes and buffs to a bright gold finish; readily nickel/chrome/gold plated or lacquered; not anodizable — use benzotriazole or clear coating to prevent tarnish.
C27000 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 |
|---|---|---|
| CuASTM B36 / B134 range for C27000 | 63 – 68.5 | 65 |
| Pbimpurity limit | ≤ 0.1 | — |
| Feimpurity limit | ≤ 0.07 | — |
| Zn | balance | — |
C27000-H04 — frequently asked
What is C27000-H04 used for?
C27000-H04 is typically used for hardware and fasteners, lamp and lighting fixtures, eyelets and rivets and stampings. In short: low-cost general-purpose brass; stamping and drawing grade; cheaper than cartridge brass.
What is the yield strength of C27000-H04?
C27000-H04 has a typical yield strength of 425 MPa (61.6 ksi) and a tensile strength of 525 MPa (76.1 ksi) — stronger than 83% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C27000-H04 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machinability ~30 % of free-cutting C36000 — gummy, long chips; use sharp positive-rake tools, high speed, light feed and good lubrication, or specify C37700/C36000 for high-volume turning.
Can C27000-H04 be welded?
With care — weldability is rated fair (40/100). Best joined by soft soldering or silver brazing; resistance and GTAW welding are possible but zinc volatilises — use good fume extraction, low heat input and Si-bronze filler.
What surface finishes work on C27000-H04?
Polishes and buffs to a bright gold finish; readily nickel/chrome/gold plated or lacquered; not anodizable — use benzotriazole or clear coating to prevent tarnish.
Can C27000-H04 be formed, bent or molded?
Excellent cold formability in O60/H01 for deep drawing, spinning and bending; interstage anneal at 425–600 °C and stress relieve at 260–300 °C after severe forming to avoid season cracking.
What is the maximum service temperature of C27000-H04?
C27000-H04 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 C27000-H02 and C27000-O60?
H02 is the default condition — default stocked temper: balanced strength and formability for hardware, stampings, fasteners and machined parts. O60: choose for deep drawing, severe bending and spinning where maximum ductility is needed. Yield strength is 340 MPa in H02 versus 115 MPa in O60.
Sources
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- CDA Alloy Datasheet C27000 (Yellow Brass) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (copper alloys) — ASM International (2005)
- EN 1652 / EN 12164 — CuZn35, CuZn36 (CW508L/CW507L) — CEN (2016)
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.