Copper Alloy C34500-H04
Supply condition
UNS C34500
H04 = full hard
Use where maximum strength, stiffness of small-diameter rod and tight straightness matter more than any post-machining bending.
Values for the H04 condition
Other C34500 tempers and conditions
C34500 is listed in 5 conditions; see the grade overview at C34500.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for maximum ductility when the part must be bent, staked, riveted or heavily cold headed after machining. | 125 | 330 | 50 | 65 HB | 27 % IACS |
As hot extruded | Mill-finish extruded rod for large diameters or for parts that will be forged or fully machined all over. | 150 | 360 | 42 | 80 HB | 27 % IACS |
Quarter hard | Balanced temper when parts need some bending or knurling after turning but more strength than annealed rod. | 235 | 370 | 30 | 100 HB | 26 % IACS |
H02Default Half hard | Standard stocked temper for automatic screw-machine rod: best combination of straightness, chip control and strength. | 310 | 415 | 20 | 125 HB | 26 % IACS |
H04This page Full hard | Use where maximum strength, stiffness of small-diameter rod and tight straightness matter more than any post-machining bending. | 380 | 470 | 12 | 145 HB | 26 % IACS |
What is C34500-H04?
C34500-H04 is C34500 supplied in the H04 condition — use where maximum strength, stiffness of small-diameter rod and tight straightness matter more than any post-machining bending. C34500-H04 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 97 GPa (14.1 Msi). C34500-H04 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 885°C (1,625 °F). H02 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- Easy to machine — 90/100, better than 98% of copper alloy grades
- High strength — 380 MPa (55.1 ksi), better than 77% of copper alloy grades
Limitations
- Difficult to weld — 15/100, worse than 94% of copper alloy grades
- Needs corrosion protection — 52/100, worse than 93% of copper alloy grades
- Limited service temperature — 170°C (338 °F), worse than 92% of copper alloy grades
- Low stiffness — 97 GPa (14.1 Msi), worse than 88% of copper alloy grades
C34500-H04 properties
Typical room-temperature values for C34500-H04; 14 are specific to this condition. Other listed values are C34500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C34500-H04 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 885°C (1,625 °F).
Mechanical14
C34500-H04 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
C34500-H04 is rated for continuous service to 170°C (338 °F). It conducts heat at 115 W/m·K (66.4 BTU/hr·ft·°F), better than 61% of copper alloy grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
C34500-H04 conducts electricity at 26 % IACS, better than 63% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 93% of copper alloy grades.
Sustainability4
Producing a kilogram of C34500-H04 takes about 58 MJ of energy and emits 3.6 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 55%.
Manufacturability7
C34500-H04's machinability is excellent (90/100, better than 98% of copper alloy grades); weldability poor (15/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C34500-H04
Is C34500 easy to machine?
Excellent free-cutting behaviour (~90 % of C36000); use zero-to-negative rake brass tooling, high speeds, light lubrication, and expect short powdery chips.
Can C34500 be welded?
Fusion welding is not recommended — lead causes hot cracking; join by soft soldering or silver brazing, or use mechanical fastening.
Can C34500 be formed, bent or molded?
Hot extrudes and hot forges well at 650–750 °C; cold bending and riveting only in O60/H01 tempers and with generous bend radii.
What surface finishes work on C34500?
Bright-dips, buffs and barrel-polishes to a bright brass lustre; readily nickel/chrome or tin electroplated, and lacquered to prevent tarnish — not anodizable.
C34500 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 |
|---|---|---|
| CuCu + named elements ≥ 99.6 % | 62 – 65 | 63.5 |
| Pbfree-machining phase | 1.5 – 2.5 | 2 |
| Fe | ≤ 0.15 | — |
| Znremainder, nominally ~34.5 % | balance | — |
C34500-H04 — frequently asked
What is C34500-H04 used for?
C34500-H04 is typically used for screw machine parts, hardware and fittings. In short: near-C36000 machinability; free-cutting brass rod; not fusion weldable.
What is the yield strength of C34500-H04?
C34500-H04 has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 77% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C34500-H04 easy to machine?
Yes — machinability is rated excellent (90/100, better than 98% of copper alloy grades). Excellent free-cutting behaviour (~90 % of C36000); use zero-to-negative rake brass tooling, high speeds, light lubrication, and expect short powdery chips.
Can C34500-H04 be welded?
Not readily — weldability is rated poor (15/100). Fusion welding is not recommended — lead causes hot cracking; join by soft soldering or silver brazing, or use mechanical fastening.
What surface finishes work on C34500-H04?
Bright-dips, buffs and barrel-polishes to a bright brass lustre; readily nickel/chrome or tin electroplated, and lacquered to prevent tarnish — not anodizable.
Can C34500-H04 be formed, bent or molded?
Hot extrudes and hot forges well at 650–750 °C; cold bending and riveting only in O60/H01 tempers and with generous bend radii.
What is the maximum service temperature of C34500-H04?
C34500-H04 is rated for continuous use to about 170°C (338 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C34500-H02 and C34500-O60?
H02 is the default condition — standard stocked temper for automatic screw-machine rod: best combination of straightness, chip control and strength. O60: choose for maximum ductility when the part must be bent, staked, riveted or heavily cold headed after machining. Yield strength is 310 MPa in H02 versus 125 MPa in O60.
Sources
- ASTM B16 / B453 — Free-Cutting Brass Rod, Bar and Shapes — ASTM International (2019)
- Copper Development Association alloy datasheet C34500 — CDA (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.