Aluminum 6951-T42
Temper
AA 6951 · UNS A96951 · EN AW-6951
T42 = solution heat treated by the user and naturally aged
Applies when the fabricator (not the mill) solution treats formed parts, e.g. after brazing and quench.
Values for the T42 condition
Other 6951 tempers and conditions
6951 is listed in 12 conditions; see the grade overview at 6951.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Standard condition for clad brazing sheet that will be roll-formed into tubes/fins and then furnace brazed. | 41 | 110 | 30 | 28 HB | 50 % IACS |
As-brazed (post-CAB, naturally aged core) | The real in-service state of radiator/condenser tubes: core recrystallised by the 595–605 °C braze cycle, then naturally aged for weeks. | 70 | 165 | 20 | 45 HB | 46 % IACS |
Strain hardened, quarter hard | Light temper rolling when slightly stiffer strip is needed but deep forming is still required. | 105 | 130 | 12 | 38 HB | 50 % IACS |
T42This page Solution heat treated by the user and naturally aged | Applies when the fabricator (not the mill) solution treats formed parts, e.g. after brazing and quench. | 110 | 205 | 22 | 58 HB | 44 % IACS |
Strain hardened and partially annealed, half hard | Half-hard strength with better bend ductility than H14 — preferred for folded (B-type) brazed tube. | 120 | 150 | 10 | 44 HB | 50 % IACS |
Solution heat treated and naturally aged | Formable but pre-strengthened condition; also approximates the state of brazed parts after natural aging. | 125 | 220 | 20 | 62 HB | 43 % IACS |
Strain hardened, half hard | Common as-rolled coil temper for high-speed fin mills and welded-tube stock. | 130 | 150 | 8 | 45 HB | 50 % IACS |
Strain hardened, three-quarter hard | Stiffer strip for narrow fin stock where limited bending is acceptable. | 160 | 175 | 5 | 52 HB | 50 % IACS |
Cooled from hot working and artificially aged | Used when the braze-furnace exit cooling is fast enough to act as a quench, followed by a low-temperature age. | 170 | 210 | 12 | 68 HB | 46 % IACS |
Strain hardened, full hard | Maximum cold-worked strength; used where the strip is only slit and corrugated, not deep drawn. | 185 | 200 | 3 | 58 HB | 50 % IACS |
T6, heat treated by the user | Same target properties as T6 but achieved by heat treating O/H-temper material after fabrication or brazing. | 215 | 260 | 12 | 80 HB | 45 % IACS |
Solution heat treated and artificially aged | Peak-strength condition for structural sheet or for brazed assemblies that are re-solution treated and aged. | 230 | 270 | 13 | 82 HB | 45 % IACS |
What is 6951-T42?
6951-T42 is 6951 in the T42 temper — applies when the fabricator (not the mill) solution treats formed parts, e.g. after brazing and quench. 6951-T42 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 205 MPa (29.7 ksi) — weaker than 81% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi). 6951-T42 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 616°C (1,141 °F). O is the default condition FabDigit quotes; T42 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 22%, better than 91% of aluminum grades
- Conducts heat well — 178 W/m·K (102.8 BTU/hr·ft·°F), better than 86% of aluminum grades
- High electrical conductivity — 44 % IACS, better than 85% of aluminum grades
- Forms and bends easily — 72/100, better than 85% of aluminum grades
Limitations
- Low strength — 110 MPa (16 ksi), worse than 81% of aluminum grades
6951-T42 properties
Typical room-temperature values for 6951-T42; 19 are specific to this condition. Other listed values are 6951 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6951-T42 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 616°C (1,141 °F).
Mechanical10
6951-T42 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 205 MPa (29.7 ksi) — weaker than 81% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6951-T42 is rated for continuous service to 150°C (302 °F). It conducts heat at 178 W/m·K (102.8 BTU/hr·ft·°F), better than 86% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
6951-T42 conducts electricity at 44 % IACS, better than 85% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (56/100), better than 52% of aluminum grades.
Sustainability4
Producing a kilogram of 6951-T42 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability8
6951-T42's machinability is fair (48/100, worse than 68% of aluminum grades); weldability very good (70/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6951-T42
Is 6951 easy to machine?
Soft and gummy in O/T4 — use polished high-rake carbide, high speed and flood or MQL lubricant; T6 chips break far better.
Can 6951 be welded?
Readily GTAW/GMAW welded with 4043 filler (4047 for the clad side); avoid 5000-series filler on the Al-Si clad layer and expect strength loss in the HAZ of aged tempers.
Can 6951 be formed, bent or molded?
Excellent roll forming, fin corrugating and tube seaming in O/H24; keep bend radii ≥1t in H18 and re-anneal or use T4 for deep draws.
What surface finishes work on 6951?
Designed for CAB (Nocolok flux) or vacuum brazing at 590–605 °C; for corrosion protection use Zn arc-spray or chromate-free conversion coat plus e-coat rather than decorative anodizing, since the clad Al-Si layer anodizes unevenly.
6951 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 |
|---|---|---|
| Si | 0.2 – 0.5 | 0.35 |
| Feimpurity limit | ≤ 0.8 | 0.35 |
| Cu | 0.15 – 0.4 | 0.25 |
| Mn | ≤ 0.1 | 0.03 |
| Mg | 0.4 – 0.8 | 0.6 |
| Zn | ≤ 0.2 | 0.05 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Alremainder, ~98.3 % nominal | balance | — |
6951-T42 — frequently asked
What is 6951-T42 used for?
6951-T42 is typically used for automotive radiators, HVAC heat exchangers and brazed fin/tube assemblies. In short: brazing-sheet core alloy; highest-formability 6000 series; heat-exchanger fin stock.
What is the yield strength of 6951-T42?
6951-T42 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 205 MPa (29.7 ksi) — weaker than 81% of aluminum grades. Strength varies by condition: see the 12 listed tempers.
Is 6951-T42 easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 68% of aluminum grades). Soft and gummy in O/T4 — use polished high-rake carbide, high speed and flood or MQL lubricant; T6 chips break far better.
Can 6951-T42 be welded?
Yes — weldability is rated very good (70/100). Readily GTAW/GMAW welded with 4043 filler (4047 for the clad side); avoid 5000-series filler on the Al-Si clad layer and expect strength loss in the HAZ of aged tempers.
What surface finishes work on 6951-T42?
Designed for CAB (Nocolok flux) or vacuum brazing at 590–605 °C; for corrosion protection use Zn arc-spray or chromate-free conversion coat plus e-coat rather than decorative anodizing, since the clad Al-Si layer anodizes unevenly.
Can 6951-T42 be formed, bent or molded?
Excellent roll forming, fin corrugating and tube seaming in O/H24; keep bend radii ≥1t in H18 and re-anneal or use T4 for deep draws.
What is the maximum service temperature of 6951-T42?
6951-T42 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 6951-O and 6951-T6?
O is the default condition — standard condition for clad brazing sheet that will be roll-formed into tubes/fins and then furnace brazed. T6: peak-strength condition for structural sheet or for brazed assemblies that are re-solution treated and aged. Yield strength is 41 MPa in O versus 230 MPa in T6.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASTM B209 / B209M — Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate — ASTM International (2021)
- EN 573-3 / EN 485-2 — Aluminium and aluminium alloys: chemical composition and mechanical properties of sheet and strip — CEN (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys (brazing sheet chapter) — ASM International (1993)
- Aluminium brazing sheet product data (clad 4343/4045 on 6951/3003 core) — Rolled-product mills (e.g. Novelis / Granges / Constellium class data) (2022)
- MatWeb wrought aluminum 6951 temper property listings — MatWeb LLC (2023)
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.