Copper Alloy CuAg0.04-M20
Finish state
EN CuAg0.04
M20 = as hot rolled
Mill-finish hot-worked bar, tube and busbar where softness and maximum conductivity matter more than strength.
Values for the M20 condition
Other CuAg0.04 tempers and conditions
CuAg0.04 is listed in 9 conditions; see the grade overview at CuAg0.04.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Thermomechanically controlled processed | Cast feedstock form (EN 1978/CR011A) for subsequent hot rolling or extrusion — not a service condition. | 60 | 180 | 35 | 42 HB | 99 % IACS |
Soft annealed | Choose for maximum conductivity, deep drawing, tight bending and magnet/enamelled wire drawing stock. | 65 | 225 | 45 | 45 HB | 101 % IACS |
M20This page As hot rolled | Mill-finish hot-worked bar, tube and busbar where softness and maximum conductivity matter more than strength. | 75 | 225 | 42 | 45 HB | 100 % IACS |
Quarter hard | Light cold work for strip and rod that must still be bent or formed but need more stiffness than soft temper. | 200 | 260 | 25 | 75 HB | 99 % IACS |
Half hard | Balanced strength/formability for busbar, terminals and commutator risers that see moderate soldering heat. | 250 | 300 | 14 | 90 HB | 98.5 % IACS |
Hot rolled | Low-temperature (≈200–250 °C) treatment that removes drawing stresses while the silver keeps most of the cold-worked strength — used for commutator segments and rotor bars. | 290 | 340 | 10 | 99 HB | 99 % IACS |
H04Default Full hard | Standard stocked condition for silver-copper rod/wire — keeps its cold-worked strength through soldering and 150–250 °C service. | 310 | 360 | 8 | 105 HB | 98 % IACS |
Extra hard | Extra-hard strip/wire where maximum as-drawn strength is needed and little further forming is done. | 345 | 385 | 5 | 112 HB | 97.5 % IACS |
Spring hard | Maximum strength strip/wire for springy contacts and fine wire; almost no residual ductility. | 370 | 410 | 3 | 118 HB | 97 % IACS |
What is CuAg0.04-M20?
CuAg0.04-M20 is CuAg0.04 supplied in the M20 condition — mill-finish hot-worked bar, tube and busbar where softness and maximum conductivity matter more than strength. CuAg0.04-M20 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 91% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi). CuAg0.04-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). H04 is the default condition FabDigit quotes; M20 is available on request or by drawing note.
Advantages
- Conducts heat well — 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades
- High electrical conductivity — 100 % IACS, better than 96% of copper alloy grades
- Forms and bends easily — 92/100, better than 91% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
Limitations
- Difficult to machine — 18/100, worse than 100% of copper alloy grades
- Low strength — 75 MPa (10.9 ksi), worse than 91% of copper alloy grades
CuAg0.04-M20 properties
Typical room-temperature values for CuAg0.04-M20; 19 are specific to this condition. Other listed values are CuAg0.04 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CuAg0.04-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).
Mechanical13
CuAg0.04-M20 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 91% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
CuAg0.04-M20 is rated for continuous service to 300°C (572 °F). It conducts heat at 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades. Thermal expansion is 17.1 µm/m·K (9.5 µin/in·°F).
Electrical3
CuAg0.04-M20 conducts electricity at 100 % IACS, better than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of CuAg0.04-M20 takes about 57 MJ of energy and emits 3.9 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
CuAg0.04-M20's machinability is poor (18/100, worse than 100% of copper alloy grades); weldability fair (35/100); formability excellent (92/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CuAg0.04-M20
Is CuAg0.04 easy to machine?
Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed with low feed, generous soluble-oil coolant; hard temper machines better than annealed.
Can CuAg0.04 be welded?
Prefer GTAW/GMAW with high preheat and argon-helium shielding or resistance/friction welding; being oxygen-bearing tough pitch it must not be brazed or annealed in hydrogen-rich atmospheres (steam embrittlement).
Can CuAg0.04 be formed, bent or molded?
Excellent cold formability in O60 (deep drawing, riveting, tight bends); interstage anneals at 400–600 °C, and note the silver raises the recrystallisation temperature so anneals run hotter/longer than for Cu-ETP.
What surface finishes work on CuAg0.04?
Not anodisable — solders and brazes readily, takes tin, silver and nickel plating well; bright-polish then lacquer or allow controlled patina since bare surfaces oxidise/tarnish.
CuAg0.04 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 |
|---|---|---|
| Agsilver addition raising softening temperature; counted in the Cu+Ag total | 0.03 – 0.05 | 0.04 |
| Otough-pitch (oxygen-containing) grade; omit for the Cu-OF based CuAg0.04(OF) variants | 0.01 – 0.04 | 0.03 |
| Bi | ≤ 5×10⁻⁴ | — |
| Pb | ≤ 0.01 | — |
| Pkept low to preserve conductivity | ≤ 0 | — |
| Other impurities (total)Se+Te+Sb+As+Fe+Ni+Sn+Zn+S etc. | ≤ 0.03 | — |
| CuCu + Ag ≥ 99.90 % | balance | — |
CuAg0.04-M20 — frequently asked
What is CuAg0.04-M20 used for?
CuAg0.04-M20 is typically used for commutator bars, high-temperature electrical windings and resistance welding wheels. In short: softening-resistant tough-pitch copper; near-pure-copper conductivity; hotter service than Cu-ETP.
What is the yield strength of CuAg0.04-M20?
CuAg0.04-M20 has a typical yield strength of 75 MPa (10.9 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 91% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is CuAg0.04-M20 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 100% of copper alloy grades). Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed with low feed, generous soluble-oil coolant; hard temper machines better than annealed.
Can CuAg0.04-M20 be welded?
With care — weldability is rated fair (35/100). Prefer GTAW/GMAW with high preheat and argon-helium shielding or resistance/friction welding; being oxygen-bearing tough pitch it must not be brazed or annealed in hydrogen-rich atmospheres (steam embrittlement).
What surface finishes work on CuAg0.04-M20?
Not anodisable — solders and brazes readily, takes tin, silver and nickel plating well; bright-polish then lacquer or allow controlled patina since bare surfaces oxidise/tarnish.
Can CuAg0.04-M20 be formed, bent or molded?
Excellent cold formability in O60 (deep drawing, riveting, tight bends); interstage anneals at 400–600 °C, and note the silver raises the recrystallisation temperature so anneals run hotter/longer than for Cu-ETP.
What is the maximum service temperature of CuAg0.04-M20?
CuAg0.04-M20 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CuAg0.04-H04 and CuAg0.04-M?
H04 is the default condition — standard stocked condition for silver-copper rod/wire — keeps its cold-worked strength through soldering and 150–250 °C service. M: cast feedstock form (EN 1978/CR011A) for subsequent hot rolling or extrusion — not a service condition. Yield strength is 310 MPa in H04 versus 60 MPa in M.
Sources
- EN 13601 — Copper and copper alloys: rod, bar and wire for electrical purposes — CEN (2021)
- EN 1977 / EN 1978 — Copper drawing stock and cathodes (CR/CW designations) — CEN (2013)
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar (C10400/C10500/C10700) — ASTM (2019)
- CDA alloy datasheets C10400 / C10500 / C10700 (silver-bearing tough pitch copper) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — 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.