Copper Alloy T2-Y4
Supply condition
GB T2 · UNS C11000 · ASTM B152 · EN CW004A, Cu-ETP · JIS C1100
Choose quarter hard as the compromise for bent parts and stamped conductive tabs: 195 MPa yield with small-radius bends still possible at 98.5% IACS.
Values for the Y4 condition
Other T2 tempers and conditions
T2 is listed in 11 conditions; see the grade overview at T2.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
MDefault Thermomechanically controlled processed | Choose the soft annealed (O60) state for bending, deep drawing and forming, or wherever the full 101% IACS conductivity is needed; yield is lowest at 69 MPa. | 69 | 220 | 45 | 40 HB | 101 % IACS |
as-hot-rolled plate | Pick as-hot-rolled plate over 10 mm for welded structures and machined blanks: lowest cost per kg with near-soft properties, 215 MPa tensile and 100% IACS. | 70 | 215 | 40 | 45 HB | 100 % IACS |
Annealed to 0.050 mm grain size | Use strip annealed to a controlled 0.050 / 0.025 mm grain size for deep-drawn and cupped parts where uniform elongation and an orange-peel-free surface matter more than strength. | 76 | 230 | 42 | 42 HB | 101 % IACS |
Hard drawn | Choose the as-extruded state for busbar and heavy-wall tube when near-annealed ductility and 100% IACS are wanted without a separate anneal; yield is only 80 MPa. | 80 | 225 | 42 | 45 HB | 100 % IACS |
1/8 hard | Pick 1/8 hard sheet and strip when parts must be stiffer than annealed stock yet keep most of their formability; light cold work gives 140 MPa yield at 99% IACS. | 140 | 255 | 30 | 60 HB | 99 % IACS |
Y4This page quarter hard | Choose quarter hard as the compromise for bent parts and stamped conductive tabs: 195 MPa yield with small-radius bends still possible at 98.5% IACS. | 195 | 270 | 25 | 70 HB | 98.5 % IACS |
half hard | Use half hard, the most commonly stocked sheet, strip and bar condition, when machined surface quality and low distortion matter; 240 MPa yield limits tight bends at 14% elongation. | 240 | 290 | 14 | 80 HB | 98 % IACS |
hard (cold drawn / cold rolled) | Pick the hard cold-drawn or cold-rolled state for rod, wire and rigid busbar needing the best strength (300 MPa yield) and dimensional accuracy; bending capability is limited. | 300 | 340 | 12 | 95 HB | 97 % IACS |
extra hard | Choose extra hard strip for switch contacts and commutator segments requiring higher strength and stiffness (340 MPa yield); elongation drops to 6% and service limit to 130 °C. | 340 | 380 | 6 | 105 HB | 96.5 % IACS |
Spring hard | Use spring temper thin strip for contact springs and shielding fingers that need a high elastic limit (365 MPa yield) while still holding 96% IACS; forming is very restricted. | 365 | 400 | 4 | 110 HB | 96 % IACS |
Extra spring hard | Pick the extra spring temper only for very thin strip and foil where elasticity and 425 MPa tensile govern; at 2% elongation the material is effectively unformable. | 390 | 425 | 2 | 115 HB | 95.5 % IACS |
What is T2-Y4?
T2-Y4 is T2 supplied in the Y4 condition — choose quarter hard as the compromise for bent parts and stamped conductive tabs: 195 MPa yield with small-radius bends still possible at 98.5% IACS. T2-Y4 has a yield strength of 195 MPa (28.3 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 56% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 117 GPa (17 Msi). T2-Y4 has a density of 8.93 g/cm³ (0.323 lb/in³), heavier than 82% of copper alloy grades. It melts at 1,065°C (1,949 °F). M is the default condition FabDigit quotes; Y4 is available on request or by drawing note.
Advantages
- High electrical conductivity — 98.5 % IACS, better than 95% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Conducts heat well — 384 W/m·K (221.9 BTU/hr·ft·°F), better than 91% of copper alloy grades
- Forms and bends easily — 70/100, better than 80% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
T2-Y4 properties
Typical room-temperature values for T2-Y4; 19 are specific to this condition. Other listed values are T2 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
T2-Y4 has a density of 8.93 g/cm³ (0.323 lb/in³), heavier than 82% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical13
T2-Y4 has a yield strength of 195 MPa (28.3 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 56% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
T2-Y4 is rated for continuous service to 150°C (302 °F). It conducts heat at 384 W/m·K (221.9 BTU/hr·ft·°F), better than 91% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
T2-Y4 conducts electricity at 98.5 % IACS, better than 95% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of T2-Y4 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
T2-Y4's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability fair (40/100); formability very good (70/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with T2-Y4
Is T2 easy to machine?
In the soft temper it is gummy and throws burrs; use sharp, high-positive-rake edges, high speed and plenty of emulsion coolant, or order half-hard/hard temper for better surface quality. It contains no lead, so chips are long and tough and the machinability rating is only about 20.
Can T2 be welded?
Brazing and soft soldering are excellent. In TIG/MIG welding the residual oxygen reacts with hydrogen to form steam porosity and embrittles the heat-affected zone, so use high heat input, preheat and deoxidized filler; for gas-tight or hydrogen-atmosphere structures switch to oxygen-free TU1.
Can T2 be formed, bent or molded?
Cold formability in the annealed temper is excellent, covering deep drawing, spinning and bending down to about 0.5 t. It work-hardens quickly, so allow an intermediate anneal at 450-600 °C between forming stages.
What surface finishes work on T2?
Not anodizable. Tin, nickel or silver plating, chemical passivation (benzotriazole) or clear lacquer all work; polishing gives a mirror finish, but a dark oxide film forms naturally if left uncoated.
T2 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 |
|---|---|---|
| Oas Cu2O in tough-pitch copper; typical 0.02–0.05 % | ≤ 0.06 | 0.03 |
| Bi | ≤ 0 | — |
| Sb | ≤ 0 | — |
| As | ≤ 0 | — |
| Fe | ≤ 0.01 | — |
| Pb | ≤ 0.01 | — |
| S | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Zn | ≤ 0.01 | — |
| Sn | ≤ 0 | — |
| total impuritiesGB/T 5231 T2, oxygen excluded | ≤ 0.1 | — |
| CuCu+Ag ≥ 99.90 % (tough pitch, oxygen not counted as impurity) | ≥ 99.9 (balance) | — |
T2-Y4 — frequently asked
What is T2-Y4 used for?
T2-Y4 is typically used for busbars, electrical terminals, copper tube, gaskets and general fabrication. In short: standard 101 % IACS copper; cheapest conductive copper; best-formability soft temper.
What is the yield strength of T2-Y4?
T2-Y4 has a typical yield strength of 195 MPa (28.3 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 56% of copper alloy grades. Strength varies by condition: see the 11 listed tempers.
Is T2-Y4 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). In the soft temper it is gummy and throws burrs; use sharp, high-positive-rake edges, high speed and plenty of emulsion coolant, or order half-hard/hard temper for better surface quality. It contains no lead, so chips are long and tough and the machinability rating is only about 20.
Can T2-Y4 be welded?
With care — weldability is rated fair (40/100). Brazing and soft soldering are excellent. In TIG/MIG welding the residual oxygen reacts with hydrogen to form steam porosity and embrittles the heat-affected zone, so use high heat input, preheat and deoxidized filler; for gas-tight or hydrogen-atmosphere structures switch to oxygen-free TU1.
What surface finishes work on T2-Y4?
Not anodizable. Tin, nickel or silver plating, chemical passivation (benzotriazole) or clear lacquer all work; polishing gives a mirror finish, but a dark oxide film forms naturally if left uncoated.
Can T2-Y4 be formed, bent or molded?
Cold formability in the annealed temper is excellent, covering deep drawing, spinning and bending down to about 0.5 t. It work-hardens quickly, so allow an intermediate anneal at 450-600 °C between forming stages.
What is the maximum service temperature of T2-Y4?
T2-Y4 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 T2-M and T2-H10?
M is the default condition — choose the soft annealed (O60) state for bending, deep drawing and forming, or wherever the full 101% IACS conductivity is needed; yield is lowest at 69 MPa. H10: pick the extra spring temper only for very thin strip and foil where elasticity and 425 MPa tensile govern; at 2% elongation the material is effectively unformable. Yield strength is 69 MPa in M versus 390 MPa in H10.
Sources
- ASTM B152/B152M Copper Sheet, Strip, Plate and Rolled Bar — ASTM (2019)
- ASTM B187 Copper Bus Bar, Rod and Shapes — ASTM (2020)
- EN 13601 Copper rod, bar and wire (Cu-ETP, CW004A) — CEN (2021)
- C11000 Electrolytic Tough Pitch Copper alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties of 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.