Copper Alloy C21000-H03
Supply condition
UNS C21000 · ASTM B36 · EN CuZn5, CW500L · JIS C2100 · GB H95, H96
H03 = three-quarter hard
Intermediate step when H04 is too stiff for the required bend radius.
Values for the H03 condition
Other C21000 tempers and conditions
C21000 is listed in 10 conditions; see the grade overview at C21000.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OS050Default Annealed to 0.050 mm grain size | Standard soft strip/sheet for deep drawing, coining and bullet-jacket cupping. | 75 | 240 | 45 | 45 HB | 56 % IACS |
As hot rolled | Hot-rolled plate/bar stock for further hot or cold working; lowest cost per kg. | 85 | 250 | 45 | 50 HB | 56 % IACS |
Annealed to 0.025 mm grain size | Fine-grain soft temper when a smooth (orange-peel-free) drawn surface is required. | 95 | 260 | 42 | 55 HB | 56 % IACS |
Quarter hard | Light temper when moderate bending/forming must be kept but soft temper is too weak. | 205 | 280 | 25 | 70 HB | 55 % IACS |
Half hard | General-purpose stocked temper for stamped and mildly formed decorative/electrical parts. | 260 | 315 | 14 | 85 HB | 55 % IACS |
H03This page Three-quarter hard | Intermediate step when H04 is too stiff for the required bend radius. | 300 | 345 | 9 | 95 HB | 54 % IACS |
Full hard | Standard hard strip for flat springs, contacts and stiff trim with only gentle bends. | 340 | 380 | 5 | 105 HB | 54 % IACS |
Extra hard | Higher-strength strip for spring clips and stiff blanked parts; bends only across grain. | 385 | 420 | 4 | 115 HB | 54 % IACS |
Spring hard | Spring strip where high elastic limit with near-copper conductivity is needed. | 415 | 450 | 3 | 120 HB | 53 % IACS |
Extra spring hard | Maximum cold-worked strength available in this alloy; essentially no forming capability. | 440 | 470 | 3 | 125 HB | 53 % IACS |
What is C21000-H03?
C21000-H03 is C21000 supplied in the H03 condition — intermediate step when H04 is too stiff for the required bend radius. C21000-H03 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 61% of copper alloy grades. Elongation at break is 9% and the elastic modulus is 115 GPa (16.7 Msi). C21000-H03 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 1,055°C (1,931 °F). OS050 is the default condition FabDigit quotes; H03 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 90/100, better than 99% of copper alloy grades
- Conducts heat well — 226 W/m·K (130.6 BTU/hr·ft·°F), better than 80% of copper alloy grades
- High electrical conductivity — 54 % IACS, better than 80% of copper alloy grades
- Readily welded — 60/100, better than 76% 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 — 9%, worse than 79% of copper alloy grades
C21000-H03 properties
Typical room-temperature values for C21000-H03; 11 are specific to this condition. Other listed values are C21000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C21000-H03 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 1,055°C (1,931 °F).
Mechanical12
C21000-H03 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 61% of copper alloy grades. Elongation at break is 9% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
C21000-H03 is rated for continuous service to 150°C (302 °F). It conducts heat at 226 W/m·K (130.6 BTU/hr·ft·°F), better than 80% of copper alloy grades. Thermal expansion is 18.1 µm/m·K (10.1 µin/in·°F).
Electrical3
C21000-H03 conducts electricity at 54 % IACS, better than 80% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C21000-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%.
Manufacturability8
C21000-H03's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability good (60/100); formability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C21000-H03
Is C21000 easy to machine?
Gummy, low machinability (~20% of C36000) — use sharp positive-rake tools, high speed, generous coolant and avoid dwell; not a screw-machine alloy.
Can C21000 be welded?
Excellent for soldering and brazing; GTAW/GMAW acceptable with ERCu/CuSi filler and low heat input, resistance welding only fair due to high conductivity.
Can C21000 be formed, bent or molded?
Outstanding deep drawing, coining, spinning and severe bending in OS tempers; interanneal at 425–650 °C and stress-relieve formed parts (~200–260 °C) to prevent season cracking.
What surface finishes work on C21000?
Bright-dips, buffs and polishes to a rich gold color; readily nickel/gold/chrome plated, patinated or clear-lacquered — anodizing is not applicable.
C21000 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 + Ag counted together per ASTM B36 | 94 – 96 | 95 |
| Pbimpurity limit | ≤ 0.03 | — |
| Feimpurity limit | ≤ 0.05 | — |
| Zn | balance | — |
C21000-H03 — frequently asked
What is C21000-H03 used for?
C21000-H03 is typically used for coinage blanks, bullet jackets, architectural trim, jewelry and emblems. In short: highest-formability wrought brass; gold-color low-zinc brass; 56 % IACS conductivity.
What is the yield strength of C21000-H03?
C21000-H03 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 61% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C21000-H03 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy, low machinability (~20% of C36000) — use sharp positive-rake tools, high speed, generous coolant and avoid dwell; not a screw-machine alloy.
Can C21000-H03 be welded?
Yes — weldability is rated good (60/100). Excellent for soldering and brazing; GTAW/GMAW acceptable with ERCu/CuSi filler and low heat input, resistance welding only fair due to high conductivity.
What surface finishes work on C21000-H03?
Bright-dips, buffs and polishes to a rich gold color; readily nickel/gold/chrome plated, patinated or clear-lacquered — anodizing is not applicable.
Can C21000-H03 be formed, bent or molded?
Outstanding deep drawing, coining, spinning and severe bending in OS tempers; interanneal at 425–650 °C and stress-relieve formed parts (~200–260 °C) to prevent season cracking.
What is the maximum service temperature of C21000-H03?
C21000-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 C21000-OS050 and C21000-H10?
OS050 is the default condition — standard soft strip/sheet for deep drawing, coining and bullet-jacket cupping. H10: maximum cold-worked strength available in this alloy; essentially no forming capability. Yield strength is 75 MPa in OS050 versus 440 MPa in H10.
Sources
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- CDA Alloy Datasheet C21000 (Gilding, 95%) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- EN 1652 / CW500L (CuZn5) copper and copper alloy plate, sheet and strip — CEN (1998)
- GB/T 2059 / GB/T 2040 (H95) (2017)
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.