Copper Alloy C10300-H04
Supply condition
UNS C10300 · EN CW020A
H04 = full hard
Standard hard temper for bus bar, terminals and flat parts needing stiffness and flatness with minimal forming.
Values for the H04 condition
Other C10300 tempers and conditions
C10300 is listed in 14 conditions; see the grade overview at C10300.
Compare all 14 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled and annealed | Heavy plate and bar softened after hot rolling for maximum conductivity, machining stability and formability. | 62 | 225 | 48 | 40 HB | 101 % IACS |
O60Default Soft annealed | Baseline soft temper for maximum conductivity, deep drawing, bending and brazed/vacuum assemblies. | 69 | 230 | 45 | 42 HB | 101 % IACS |
As hot rolled | Mill temper of hot-rolled plate/bar and bus bar where surface finish and flatness matter more than temper control. | 90 | 235 | 40 | 45 HB | 101 % IACS |
Light annealed | Partially softened temper when a little more strength than dead-soft is wanted with good formability. | 100 | 240 | 40 | 48 HB | 101 % IACS |
1/8 hard | Very light cold work for gaskets and formed parts needing slightly more spring-back control than annealed. | 170 | 250 | 30 | 60 HB | 100.5 % IACS |
Light drawn | Lightly drawn tube or rod: stiffer than annealed but still bendable by hand tooling. | 180 | 260 | 25 | 70 HB | 100 % IACS |
Quarter hard | Quarter-hard strip/sheet balancing moderate strength with 90° bending in most directions. | 205 | 262 | 25 | 68 HB | 100 % IACS |
Half hard | Most-stocked cold-worked sheet/bar temper: usable strength with limited forming (gentle bends). | 245 | 280 | 14 | 78 HB | 100 % IACS |
Three-quarter hard | Intermediate step to full hard when a flatter, stiffer strip is needed but full hard is too brittle to form. | 265 | 295 | 10 | 85 HB | 99.5 % IACS |
Hard drawn | Drawn-to-size hard rod/wire/tube for rigid conductors, machined electrodes and pressure tubing. | 275 | 315 | 10 | 90 HB | 99 % IACS |
H04This page Full hard | Standard hard temper for bus bar, terminals and flat parts needing stiffness and flatness with minimal forming. | 280 | 315 | 6 | 92 HB | 99 % IACS |
Extra hard | Extra-hard strip for flat springs, contacts and stamped parts where elastic stiffness dominates. | 315 | 345 | 4 | 100 HB | 98.5 % IACS |
Spring hard | Spring temper strip for conductive springs, shields and clips; forming limited to large-radius bends. | 340 | 365 | 4 | 105 HB | 98 % IACS |
Extra spring hard | Maximum cold-worked strength for thin conductive spring strip; essentially non-formable and softens easily on heating. | 350 | 380 | 3 | 110 HB | 97.5 % IACS |
What is C10300-H04?
C10300-H04 is C10300 supplied in the H04 condition — standard hard temper for bus bar, terminals and flat parts needing stiffness and flatness with minimal forming. C10300-H04 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 6% and the elastic modulus is 117 GPa (17 Msi). C10300-H04 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F). O60 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- High electrical conductivity — 99 % IACS, better than 95% of copper alloy grades
- Conducts heat well — 386 W/m·K (223 BTU/hr·ft·°F), better than 93% of copper alloy grades
- Readily welded — 75/100, better than 89% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Limited ductility — 6%, worse than 89% of copper alloy grades
C10300-H04 properties
Typical room-temperature values for C10300-H04; 16 are specific to this condition. Other listed values are C10300 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C10300-H04 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F).
Mechanical13
C10300-H04 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 6% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C10300-H04 is rated for continuous service to 150°C (302 °F). It conducts heat at 386 W/m·K (223 BTU/hr·ft·°F), better than 93% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C10300-H04 conducts electricity at 99 % IACS, better than 95% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C10300-H04 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 25%.
Manufacturability8
C10300-H04's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability very good (75/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C10300-H04
Is C10300 easy to machine?
Gummy and low-rated (~20% of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and avoid dwell to prevent smearing.
Can C10300 be welded?
Excellent for GTAW/GMAW/EBW and brazing — the P deoxidation prevents hydrogen embrittlement; high heat input or preheat needed because of the 390 W/m·K conductivity.
Can C10300 be formed, bent or molded?
Annealed temper deep draws, spins and bends superbly; hard tempers need large bend radii and interstage annealing at 400–600 °C.
What surface finishes work on C10300?
Not anodisable — electroplate Ni/Ag/Sn, chemically brighten or polish; bare surfaces tarnish and benefit from lacquer or benzotriazole treatment.
C10300 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 |
|---|---|---|
| Pcontrolled low-phosphorus deoxidation per ASTM B224 / EN Cu-OFP | 0 – 0.01 | 0 |
| Otypical residual oxygen, oxygen-free melting practice | ≤ 0 | 5×10⁻⁴ |
| CuCu + Ag, min; oxygen-free (no deoxidant residue other than P) | ≥ 99.95 (balance) | — |
C10300-H04 — frequently asked
What is C10300-H04 used for?
C10300-H04 is typically used for nuclear waste canisters, high-integrity welded conductors and hydrogen-service piping. In short: weld-grade oxygen-free copper; 101 % IACS conductivity; hydrogen-embrittlement resistant.
What is the yield strength of C10300-H04?
C10300-H04 has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 59% of copper alloy grades. Strength varies by condition: see the 14 listed tempers.
Is C10300-H04 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and low-rated (~20% of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and avoid dwell to prevent smearing.
Can C10300-H04 be welded?
Yes — weldability is rated very good (75/100). Excellent for GTAW/GMAW/EBW and brazing — the P deoxidation prevents hydrogen embrittlement; high heat input or preheat needed because of the 390 W/m·K conductivity.
What surface finishes work on C10300-H04?
Not anodisable — electroplate Ni/Ag/Sn, chemically brighten or polish; bare surfaces tarnish and benefit from lacquer or benzotriazole treatment.
Can C10300-H04 be formed, bent or molded?
Annealed temper deep draws, spins and bends superbly; hard tempers need large bend radii and interstage annealing at 400–600 °C.
What is the maximum service temperature of C10300-H04?
C10300-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 C10300-O60 and C10300-H10?
O60 is the default condition — baseline soft temper for maximum conductivity, deep drawing, bending and brazed/vacuum assemblies. H10: maximum cold-worked strength for thin conductive spring strip; essentially non-formable and softens easily on heating. Yield strength is 69 MPa in O60 versus 350 MPa in H10.
Sources
- ASTM B224 Standard Classification of Coppers — ASTM International (2021)
- ASTM B152/B152M Copper Sheet, Strip, Plate and Rolled Bar — ASTM International (2019)
- EN 13601 / EN 1652 Copper and copper alloys — Cu-OFP (CW020A) — CEN (2013)
- CDA Alloy Database — C10300 Oxygen-Free Extra-Low Phosphorus Copper — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Copper and Copper 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.