Copper Alloy C26800-M20
Finish state
UNS C26800 · EN CW506L, CuZn33
M20 = as hot rolled
Mill hot-rolled plate/bar condition — soft, cheap, for parts that will be machined or further worked.
Values for the M20 condition
Other C26800 tempers and conditions
C26800 is listed in 9 conditions; see the grade overview at C26800.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OS050Default Annealed to 0.050 mm grain size | Softest standard stock condition — pick for deep drawing, spinning, severe bending and re-forming. | 110 | 324 | 55 | 55 HB | 27 % IACS |
M20This page As hot rolled | Mill hot-rolled plate/bar condition — soft, cheap, for parts that will be machined or further worked. | 117 | 331 | 50 | 58 HB | 27 % IACS |
Quarter hard | Light cold work — still very formable but with useful added stiffness for stamped brackets and trim. | 276 | 379 | 43 | 90 HB | 27 % IACS |
Half hard | The workhorse temper: good strength with enough ductility for 90° bends across the grain. | 358 | 427 | 23 | 115 HB | 27 % IACS |
Three-quarter hard | Choose when higher yield is needed but the part still requires mild forming or riveting. | 400 | 476 | 15 | 130 HB | 26.5 % IACS |
Full hard | Standard hard sheet/strip for flat stamped parts, washers and contacts needing stiffness, minimal forming. | 427 | 524 | 8 | 145 HB | 26.5 % IACS |
Extra hard | High-strength strip for flat springs and shims where only slight forming is required. | 462 | 586 | 5 | 160 HB | 26 % IACS |
Spring hard | Spring strip: highest practical elastic limit for clips, contact fingers and diaphragms. | 500 | 634 | 4 | 170 HB | 26 % IACS |
Extra spring hard | Maximum-strength thin strip; bend only along generous radii parallel to rolling direction. | 540 | 683 | 3 | 180 HB | 26 % IACS |
What is C26800-M20?
C26800-M20 is C26800 supplied in the M20 condition — mill hot-rolled plate/bar condition — soft, cheap, for parts that will be machined or further worked. C26800-M20 has a yield strength of 117 MPa (17 ksi) and a tensile strength of 331 MPa (48 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 105 GPa (15.2 Msi). C26800-M20 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 909°C (1,668 °F). OS050 is the default condition FabDigit quotes; M20 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 50%, better than 97% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Forms and bends easily — 85/100, better than 85% of copper alloy grades
Limitations
- Low strength — 117 MPa (17 ksi), worse than 80% of copper alloy grades
C26800-M20 properties
Typical room-temperature values for C26800-M20; 11 are specific to this condition. Other listed values are C26800 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C26800-M20 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 909°C (1,668 °F).
Mechanical12
C26800-M20 has a yield strength of 117 MPa (17 ksi) and a tensile strength of 331 MPa (48 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C26800-M20 is rated for continuous service to 250°C (482 °F). It conducts heat at 121 W/m·K (69.9 BTU/hr·ft·°F), better than 68% of copper alloy grades. Thermal expansion is 20 µm/m·K (11.1 µin/in·°F).
Electrical3
C26800-M20 conducts electricity at 27 % IACS, better than 67% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C26800-M20 takes about 62 MJ of energy and emits 3.8 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 60%.
Manufacturability8
C26800-M20's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability fair (45/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C26800-M20
Is C26800 easy to machine?
Machinability only ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake carbide, high speed, light feeds, or switch to C36000 if turning-intensive.
Can C26800 be welded?
Resistance and oxy-fuel brazing/soldering are excellent; fusion welding is fair — zinc fume and porosity require silicon-bronze filler, low heat input and ventilation.
Can C26800 be formed, bent or molded?
Outstanding cold formability in OS050/H01 for deep drawing, spinning and stamping; interanneal ~450–600 °C and stress-relieve ~260–300 °C after forming to prevent season cracking.
What surface finishes work on C26800?
Not anodizable; bright-dips, tumbling and buffing give a high polish — protect with lacquer or clear coat, or nickel/chrome/PVD plate for wear and tarnish resistance.
C26800 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 |
|---|---|---|
| Cuincludes Ag | 64 – 68.5 | 66 |
| Pbimpurity limit | ≤ 0.15 | — |
| Feimpurity limit | ≤ 0.05 | — |
| Zn | balance | — |
C26800-M20 — frequently asked
What is C26800-M20 used for?
C26800-M20 is typically used for fasteners, plumbing hardware, electrical hardware and stamped and drawn parts. In short: top-formability yellow brass; 55 % elongation annealed; standard drawing and stamping brass.
What is the yield strength of C26800-M20?
C26800-M20 has a typical yield strength of 117 MPa (17 ksi) and a tensile strength of 331 MPa (48 ksi) — weaker than 80% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C26800-M20 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Machinability only ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake carbide, high speed, light feeds, or switch to C36000 if turning-intensive.
Can C26800-M20 be welded?
With care — weldability is rated fair (45/100). Resistance and oxy-fuel brazing/soldering are excellent; fusion welding is fair — zinc fume and porosity require silicon-bronze filler, low heat input and ventilation.
What surface finishes work on C26800-M20?
Not anodizable; bright-dips, tumbling and buffing give a high polish — protect with lacquer or clear coat, or nickel/chrome/PVD plate for wear and tarnish resistance.
Can C26800-M20 be formed, bent or molded?
Outstanding cold formability in OS050/H01 for deep drawing, spinning and stamping; interanneal ~450–600 °C and stress-relieve ~260–300 °C after forming to prevent season cracking.
What is the maximum service temperature of C26800-M20?
C26800-M20 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C26800-OS050 and C26800-H10?
OS050 is the default condition — softest standard stock condition — pick for deep drawing, spinning, severe bending and re-forming. H10: maximum-strength thin strip; bend only along generous radii parallel to rolling direction. Yield strength is 110 MPa in OS050 versus 540 MPa in H10.
Sources
- ASTM B36/B36M — Brass Plate, Sheet, Strip, and Rolled Bar — ASTM International (2018)
- EN 1652 / EN 12164 — CuZn33 (CW506L) — CEN (2016)
- CDA Alloy Datasheet C26800 (Yellow Brass 66/34) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.