Copper Alloy C11000-M20
Finish state
UNS C11000 · ASTM B152 · EN Cu-ETP, CW004A · JIS C1100 · GB T2
M20 = as hot rolled
Cheapest hot-worked plate, bar and busbar where dimensional tolerance and surface are secondary.
Values for the M20 condition
Other C11000 tempers and conditions
C11000 is listed in 12 conditions; see the grade overview at C11000.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Default soft temper for deep drawing, bending, riveted busbar tabs and maximum conductivity. | 69 | 221 | 45 | 45 HB | 101 % IACS |
Hot isostatic pressed | Post-processing route that closes AM/PM porosity to restore near-wrought density, conductivity and ductility. | 75 | 220 | 45 | 47 HB | 99 % IACS |
M20This page As hot rolled | Cheapest hot-worked plate, bar and busbar where dimensional tolerance and surface are secondary. | 90 | 230 | 42 | 50 HB | 100 % IACS |
L-PBF / binder-jet additive, as-built | Pick for AM heat exchangers, inductors and RF parts printed from C11000/pure-Cu powder (green or IR laser, high-density parameter set). | 130 | 215 | 35 | 62 HB | 90 % IACS |
Eighth hard | Slight cold work to flatten strip and stiffen it while keeping ample bend ductility. | 195 | 250 | 30 | 65 HB | 99 % IACS |
Quarter hard | Moderate stiffness with good bendability — roofing, gaskets, formed contacts. | 205 | 262 | 25 | 75 HB | 98 % IACS |
Half hard | Most common cold-worked temper for busbar, terminals and machined parts needing some strength. | 250 | 290 | 14 | 85 HB | 98 % IACS |
cold worked then low-temperature stress relief (~180–250 °C) | Use when machined or formed cold-worked copper must stay dimensionally stable without full softening. | 265 | 310 | 12 | 90 HB | 99 % IACS |
Full hard | Hard drawn rod, wire and strip for maximum strength/stiffness with only minor conductivity loss. | 310 | 345 | 6 | 100 HB | 97 % IACS |
Extra hard | Between hard and spring temper for stiff flat springs and stamped contacts. | 330 | 365 | 5 | 105 HB | 97 % IACS |
Spring hard | Spring-hard strip and wire for conductive springs, clips and EMI gaskets. | 345 | 380 | 4 | 110 HB | 96 % IACS |
Extra spring hard | Maximum cold-worked strength available in ETP strip/wire; almost no bend ductility. | 365 | 395 | 3 | 115 HB | 96 % IACS |
What is C11000-M20?
C11000-M20 is C11000 supplied in the M20 condition — cheapest hot-worked plate, bar and busbar where dimensional tolerance and surface are secondary. C11000-M20 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 88% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi). C11000-M20 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). O is the default condition FabDigit quotes; M20 is available on request or by drawing note.
Advantages
- High electrical conductivity — 100 % IACS, better than 96% of copper alloy grades
- Conducts heat well — 388 W/m·K (224.2 BTU/hr·ft·°F), better than 95% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Forms and bends easily — 90/100, better than 89% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
Limitations
- Low strength — 90 MPa (13.1 ksi), worse than 88% of copper alloy grades
- Difficult to machine — 25/100, worse than 86% of copper alloy grades
C11000-M20 properties
Typical room-temperature values for C11000-M20; 20 are specific to this condition. Other listed values are C11000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C11000-M20 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
C11000-M20 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 88% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C11000-M20 is rated for continuous service to 200°C (392 °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 µm/m·K (9.44 µin/in·°F).
Electrical3
C11000-M20 conducts electricity at 100 % IACS, better than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C11000-M20 takes about 53 MJ of energy and emits 3.6 kg of CO₂ — less than 85% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C11000-M20's machinability is poor (25/100, worse than 86% of copper alloy grades); weldability fair (35/100); formability excellent (90/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C11000-M20
Is C11000 easy to machine?
Gummy and abrasive to tool edges — use sharp positive-rake carbide, high speed, low feed, plenty of soluble-oil coolant; H02/H04 tempers cut far better than annealed.
Can C11000 be welded?
Prefer brazing or soldering; for fusion use GTAW/GMAW with high preheat and Cu-Si/Cu-Sn filler, but oxygen content makes the HAZ prone to hydrogen embrittlement and porosity — specify C10100/C10200 if welding is critical.
Can C11000 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, spin, roll form, tight bends); anneal 375–650 °C between severe operations and expect rapid work hardening.
What surface finishes work on C11000?
Not anodizable — bright-dip/pickle then tin, nickel or silver plate for contacts, or lacquer/patinate for architecture; polishes to a high lustre but tarnishes quickly if bare.
C11000 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 |
|---|---|---|
| Oresidual oxygen inherent to tough-pitch copper; not limited by ASTM B5 | 0.02 – 0.05 | 0.03 |
| Agcounted as copper | ≈ 0 | 0 |
| BiGB/T 5231 T2 limit | ≤ 0 | 5×10⁻⁴ |
| PbGB/T 5231 T2 limit | ≤ 0.01 | 0 |
| Sb | ≤ 0 | — |
| As | ≤ 0 | — |
| Fe | ≤ 0.01 | 0 |
| S | ≤ 0.01 | 0 |
| CuCu + Ag, 99.90 % min per ASTM B5 / GB/T T2 | ≥ 99.9 (balance) | — |
C11000-M20 — frequently asked
What is C11000-M20 used for?
C11000-M20 is typically used for electrical busbars, grounding straps and connectors, terminals and cable lugs, heat-sink bases and cold plates, switchgear and commutator contacts and transformer and motor windings. In short: industrial standard pure copper.
What is the yield strength of C11000-M20?
C11000-M20 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 88% of copper alloy grades. Strength varies by condition: see the 12 listed tempers.
Is C11000-M20 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 86% of copper alloy grades). Gummy and abrasive to tool edges — use sharp positive-rake carbide, high speed, low feed, plenty of soluble-oil coolant; H02/H04 tempers cut far better than annealed.
Can C11000-M20 be welded?
With care — weldability is rated fair (35/100). Prefer brazing or soldering; for fusion use GTAW/GMAW with high preheat and Cu-Si/Cu-Sn filler, but oxygen content makes the HAZ prone to hydrogen embrittlement and porosity — specify C10100/C10200 if welding is critical.
What surface finishes work on C11000-M20?
Not anodizable — bright-dip/pickle then tin, nickel or silver plate for contacts, or lacquer/patinate for architecture; polishes to a high lustre but tarnishes quickly if bare.
Can C11000-M20 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, spin, roll form, tight bends); anneal 375–650 °C between severe operations and expect rapid work hardening.
What is the maximum service temperature of C11000-M20?
C11000-M20 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 C11000-O and C11000-H10?
O is the default condition — default soft temper for deep drawing, bending, riveted busbar tabs and maximum conductivity. H10: maximum cold-worked strength available in ETP strip/wire; almost no bend ductility. Yield strength is 69 MPa in O versus 365 MPa in H10.
Can FabDigit make parts in C11000-M20?
Yes — C11000-M20 is available for CNC machining, sheet metal and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar — ASTM (2019)
- ASTM B187/B187M — Copper Bus Bar, Rod and Shapes — ASTM (2020)
- ASTM B5 — Electrolytic Tough Pitch Copper Refinery Shapes — ASTM (2016)
- EN 13601 / CW004A Cu-ETP — CEN (2021)
- C11000 alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- Pure copper (Cu) L-PBF powder datasheets — various AM powder suppliers (2024)
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.