Copper Alloy C12600-H03
Supply condition
UNS C12600
H03 = three-quarter hard
Intermediate step where H02 is too soft but full hard would crack on the required bend.
Values for the H03 condition
Other C12600 tempers and conditions
C12600 is listed in 15 conditions; see the grade overview at C12600.
Compare all 15 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for deep drawing, spinning, tight bending, gaskets and flexible braid/laminated bus. | 70 | 220 | 45 | 45 HB | 98 % IACS |
As hot rolled | Cheapest mill condition for thick plate, bus bar blanks and hot-extruded shapes where softness is acceptable. | 75 | 225 | 45 | 45 HB | 98 % IACS |
Annealed to 0.050 mm grain size | Grain-size-controlled soft sheet/strip for severe drawing without orange peel. | 76 | 230 | 45 | 45 HB | 98 % IACS |
Annealed to 0.025 mm grain size | Fine-grain soft strip for shallow forming with better surface finish and slightly higher strength. | 85 | 240 | 42 | 50 HB | 98 % IACS |
1/8 hard | Slight stiffening while keeping most of the soft-temper formability (roofing, flashing, formed bus). | 195 | 250 | 30 | 65 HB | 97 % IACS |
Light drawn | Tube temper giving some stiffness while still allowing bending and flaring. | 195 | 250 | 25 | 65 HB | 97 % IACS |
Quarter hard | Good balance of bendability and stiffness for brackets, terminals and light formed parts. | 205 | 260 | 25 | 75 HB | 97 % IACS |
Drawn, general purpose | Standard hard-drawn tube condition for straight-length plumbing and pressure lines. | 220 | 280 | 20 | 80 HB | 97 % IACS |
Half hard | Most common stocked strip/plate temper when moderate strength plus some bending is needed. | 250 | 290 | 14 | 85 HB | 97 % IACS |
H03This page Three-quarter hard | Intermediate step where H02 is too soft but full hard would crack on the required bend. | 275 | 315 | 10 | 90 HB | 97 % IACS |
H04Default Full hard | Default stock condition for bus bar, rod, hard-drawn wire and plate needing strength and stiffness with minimal forming. | 310 | 345 | 6 | 95 HB | 97 % IACS |
Extra hard | For flat springs, clips and contacts where higher yield matters more than ductility. | 340 | 365 | 5 | 100 HB | 96 % IACS |
Spring hard | Maximum practical strength in strip form for spring contacts and shielding fingers. | 350 | 380 | 4 | 105 HB | 96 % IACS |
Extra spring hard | Heaviest cold reduction offered on strip; bend only along, not across, the rolling direction. | 365 | 395 | 4 | 108 HB | 96 % IACS |
Hard drawn | Heavily drawn wire/rod for overhead conductors, grounding conductors and stranded cable. | 380 | 415 | 2 | 110 HB | 96 % IACS |
What is C12600-H03?
C12600-H03 is C12600 supplied in the H03 condition — intermediate step where H02 is too soft but full hard would crack on the required bend. C12600-H03 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 117 GPa (17 Msi). C12600-H03 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F). H04 is the default condition FabDigit quotes; H03 is available on request or by drawing note.
Advantages
- Conducts heat well — 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades
- High electrical conductivity — 97 % IACS, better than 92% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Limited ductility — 10%, worse than 76% of copper alloy grades
C12600-H03 properties
Typical room-temperature values for C12600-H03; 20 are specific to this condition. Other listed values are C12600 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C12600-H03 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical12
C12600-H03 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 57% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C12600-H03 is rated for continuous service to 150°C (302 °F). It conducts heat at 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
C12600-H03 conducts electricity at 97 % IACS, better than 92% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C12600-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
C12600-H03's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability poor (32/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C12600-H03
Is C12600 easy to machine?
Gummy and low rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and chip breakers; consider C14500/C36000 if heavy machining is required.
Can C12600 be welded?
Oxygen-bearing copper is prone to hydrogen embrittlement and porosity — prefer GTAW/GMAW with deoxidized filler (ERCu), preheat 200–500 °C on thick sections, and avoid reducing/H2 atmospheres above ~370 °C; brazing and soldering are excellent.
Can C12600 be formed, bent or molded?
Outstanding cold formability in O60/OS tempers (deep drawing, spinning, roll forming); interstage anneal at 400–600 °C when reduction exceeds ~60 %.
What surface finishes work on C12600?
Cannot be anodized; polishes to a bright finish but tarnishes — protect with clear lacquer/benzotriazole, or tin, nickel or silver plate for contacts and bus joints.
C12600 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 |
|---|---|---|
| Ocuprous oxide present as dispersed Cu2O; not usually a spec limit | 0.02 – 0.05 | 0.04 |
| Sbimpurity limit, typical FRTP practice | ≤ 0 | — |
| Asimpurity limit | ≤ 0.01 | — |
| Biimpurity limit | ≤ 0 | — |
| Pbimpurity limit | ≤ 0.01 | — |
| Feimpurity limit | ≤ 0.03 | — |
| Niimpurity limit | ≤ 0.05 | — |
| Simpurity limit | ≤ 0 | — |
| CuCu + Ag, remainder; fire-refined tough pitch, oxygen-bearing | ≥ 99.9 (balance) | — |
C12600-H03 — frequently asked
What is C12600-H03 used for?
C12600-H03 is typically used for wire products, general fabrication and roofing sheet. In short: tighter purity than C12500; 97 % IACS commercial copper; wide temper range on file.
What is the yield strength of C12600-H03?
C12600-H03 has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — stronger than 57% of copper alloy grades. Strength varies by condition: see the 15 listed tempers.
Is C12600-H03 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Gummy and low rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed, generous coolant and chip breakers; consider C14500/C36000 if heavy machining is required.
Can C12600-H03 be welded?
Not readily — weldability is rated poor (32/100). Oxygen-bearing copper is prone to hydrogen embrittlement and porosity — prefer GTAW/GMAW with deoxidized filler (ERCu), preheat 200–500 °C on thick sections, and avoid reducing/H2 atmospheres above ~370 °C; brazing and soldering are excellent.
What surface finishes work on C12600-H03?
Cannot be anodized; polishes to a bright finish but tarnishes — protect with clear lacquer/benzotriazole, or tin, nickel or silver plate for contacts and bus joints.
Can C12600-H03 be formed, bent or molded?
Outstanding cold formability in O60/OS tempers (deep drawing, spinning, roll forming); interstage anneal at 400–600 °C when reduction exceeds ~60 %.
What is the maximum service temperature of C12600-H03?
C12600-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 C12600-H04 and C12600-O60?
H04 is the default condition — default stock condition for bus bar, rod, hard-drawn wire and plate needing strength and stiffness with minimal forming. O60: choose for deep drawing, spinning, tight bending, gaskets and flexible braid/laminated bus. Yield strength is 310 MPa in H04 versus 70 MPa in O60.
Sources
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar — ASTM International (2019)
- ASTM B187/B187M — Copper Bus Bar, Rod and Shapes — ASTM International (2020)
- ASTM B49 — Copper Rod for Electrical Purposes — ASTM International (2020)
- CDA Standard Designations for Wrought and Cast Copper and Copper Alloys (C1xxxx series datasheets) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — 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.