Copper Alloy C21000
UNS C21000 · ASTM B36 · EN CuZn5, CW500L · JIS C2100 · GB H95, H96
C21000 is a 95/5 copper-zinc alpha brass (gilding metal, CuZn5, CW500L) that gains strength only by cold work and is stocked as strip, sheet, rod and wire in OS050 through H10 tempers.
Reference datasheet — C21000 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the OS050 condition
C21000 tempers and conditions
C21000 is supplied in 10 conditions, soft to hard. OS050 is the default FabDigit quotes; the values on this page are for it.
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 |
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?
C21000 is a 95/5 copper-zinc alpha brass (gilding metal, CuZn5, CW500L) that gains strength only by cold work and is stocked as strip, sheet, rod and wire in OS050 through H10 tempers. Engineers select it for a formability score of 97 — the highest in the wrought brass group — a gold-like color and 56 % IACS electrical conductivity, which suits coining, deep drawing and severe bending. Annealed strength is modest at 240 MPa tensile, 75 MPa yield, 45 % elongation and 45 HB, service is capped near 200 °C, and machinability is only about 20 % of C36000, so specify C36000 where turning dominates. C21000 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). C21000 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 91% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 115 GPa (16.7 Msi).
What is C21000 used for?
- coinage blanks
- bullet jackets
- architectural trim
- jewelry
- emblems
Advantages
- Polishes to a fine finish — 90/100, better than 99% of copper alloy grades
- Forms and bends easily — 97/100, better than 97% of copper alloy grades
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
- High electrical conductivity — 56 % IACS, better than 81% of copper alloy grades
- Conducts heat well — 226 W/m·K (130.6 BTU/hr·ft·°F), better than 80% of copper alloy grades
Limitations
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Low strength — 75 MPa (10.9 ksi), worse than 91% of copper alloy grades
C21000 properties
Typical room-temperature values for C21000-OS050; bars are the position among copper alloy grades.
Physical3
C21000 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 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 91% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
C21000 is rated for continuous service to 200°C (392 °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 conducts electricity at 56 % IACS, better than 81% 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 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's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability good (60/100); formability excellent (97/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C21000 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C21000
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.
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 |
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.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C21000 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B36
- EN / DIN / Werkstoff-Nr.
- CuZn5CW500L
- GB (China)
- H95H96
- JIS
- C2100
How much does C21000 cost?
C21000 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C21000 — frequently asked
What is C21000 used for?
C21000 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?
C21000 has a typical yield strength of 75 MPa (10.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 91% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C21000 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 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?
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 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?
C21000 is rated for continuous use to about 200°C (392 °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.
How much does C21000 cost?
C21000 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.