Aluminum 2024-T72
Precip hard
AA 2024 · UNS A92024 · EN AlCu4Mg1, AlCu4MgSi1 · JIS A2024, Super Duralumin · GB 2A12, LY12
T72 = overaged
Rarely supplied overaged condition used where exfoliation/SCC resistance matters more than peak strength.
Values for the T72 condition
Other 2024 tempers and conditions
2024 is listed in 18 conditions; see the grade overview at 2024.
Compare all 18 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest, most formable condition — pick it for severe forming/deep drawing, then solution treat and age to T4/T6. | 75 | 185 | 20 | 47 HB | 50 % IACS |
Solution heat treated and naturally aged by the user | Applies to O or T-temper stock re-solution treated and naturally aged by the fabricator; slightly lower guaranteed strength than mill T3/T4. | 275 | 440 | 20 | 112 HB | 30 % IACS |
Solution heat treated and naturally aged | Choose for bar, rod, extrusions and parts formed after solution treatment, where moderate forming and high strength are both needed. | 325 | 470 | 20 | 120 HB | 30 % IACS |
T3, stress relieved by stretching | The standard tooling/aerospace plate condition — low residual stress means far less distortion when machining pockets and ribs. | 325 | 470 | 19 | 120 HB | 30 % IACS |
Extruded T3 stress-relieved by stretching with minor straightening | Same as T3510 but with limited straightening allowed — the usual purchase condition for 2024 aerospace extrusions. | 330 | 460 | 12 | 118 HB | 30 % IACS |
Extruded T3 stress-relieved by stretching | Extruded rod, bar and shapes with residual stress removed by stretching; use where straightness tolerance is not critical. | 330 | 460 | 12 | 118 HB | 30 % IACS |
T3Default Solution heat treated, cold worked and naturally aged | The standard aerospace sheet condition: best combination of strength, fatigue life and damage tolerance; most widely stocked. | 345 | 483 | 18 | 120 HB | 30 % IACS |
T6, heat treated by the user | For parts heat treated after forming/machining from O or annealed stock; properties similar to mill T6. | 345 | 442 | 8 | 120 HB | 37 % IACS |
T72This page Overaged | Rarely supplied overaged condition used where exfoliation/SCC resistance matters more than peak strength. | 345 | 425 | 8 | 115 HB | 40 % IACS |
T6, stress relieved by stretching | Artificially aged (T6) 2024 plate stretched ~1.5–3 % after quench for low residual stress; higher yield and better dimensional stability than T351 but lower ductility and toughness. | 395 | 475 | 8 | 125 HB | 38 % IACS |
Solution treated, cold worked ~6 %, naturally aged | Higher-strength cold-worked sheet variant for strength-critical skins; lower ductility and formability than T3. | 395 | 495 | 13 | 130 HB | 30 % IACS |
Solution heat treated and artificially aged | Peak-aged condition mainly for bar, forgings and machined parts needing high yield strength; lower toughness and worse corrosion behaviour than T3/T4. | 400 | 470 | 10 | 125 HB | 37 % IACS |
Extruded T8 stress-relieved by stretching | Artificially aged, stress-relieved extrusions where high yield strength and stability during machining are required. | 430 | 470 | 6 | 126 HB | 38 % IACS |
Extruded T8 stress-relieved by stretching with minor straightening | As T8510 but with limited straightening; the common purchase condition for aged 2024 aerospace extrusions. | 430 | 470 | 6 | 126 HB | 38 % IACS |
T8, stress relieved by stretching | Stress-relieved, artificially aged plate/bar: highest yield strength with low machining distortion and improved SCC resistance versus T351. | 448 | 483 | 6 | 128 HB | 38 % IACS |
Solution heat treated, cold worked and artificially aged | Generic T8 condition of 2024: cold work before ageing maximises yield strength (~450 MPa) and gives the best SCC/exfoliation behaviour of the alloy, with low ductility. | 450 | 485 | 6 | 128 HB | 38 % IACS |
Solution treated, cold worked, artificially aged | High-yield sheet temper with much better intergranular-corrosion and SCC behaviour than T3; used on skins and supersonic structure. | 450 | 485 | 6 | 128 HB | 38 % IACS |
Solution treated, heavily cold worked, artificially aged | Maximum-strength 2024 sheet temper; very low ductility, so it is only used for flat or lightly formed strength-critical parts. | 490 | 517 | 6 | 135 HB | 38 % IACS |
What is 2024-T72?
2024-T72 is 2024 in the T72 condition — rarely supplied overaged condition used where exfoliation/SCC resistance matters more than peak strength. 2024-T72 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 83% of aluminum grades. Elongation at break is 8% and the elastic modulus is 73.1 GPa (10.6 Msi). 2024-T72 has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 502°C (936 °F). T3 is the default condition FabDigit quotes; T72 is available on request or by drawing note.
Advantages
- High strength — 345 MPa (50 ksi), better than 83% of aluminum grades
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
- Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 76% of aluminum grades
Limitations
- Difficult to weld — 20/100, worse than 89% of aluminum grades
2024-T72 properties
Typical room-temperature values for 2024-T72; 22 are specific to this condition. Other listed values are 2024 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2024-T72 has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 502°C (936 °F).
Mechanical14
2024-T72 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 83% of aluminum grades. Elongation at break is 8% and the elastic modulus is 73.1 GPa (10.6 Msi).
Thermal6
2024-T72 is rated for continuous service to 175°C (347 °F). It conducts heat at 159 W/m·K (91.9 BTU/hr·ft·°F), better than 74% of aluminum grades. Thermal expansion is 22.9 µm/m·K (12.7 µin/in·°F).
Electrical3
2024-T72 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 2024-T72 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
2024-T72's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (20/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2024-T72
Is 2024 easy to machine?
Excellent chip formation in T3/T351/T851 — high speeds, sharp positive-rake carbide tools and flood coolant give good finishes; annealed material is gummy.
Can 2024 be welded?
Not suitable for fusion (arc) welding due to hot cracking; join by riveting, bolting, adhesive bonding, resistance spot welding or friction stir welding.
Can 2024 be formed, bent or molded?
Form in O or freshly solution-treated (T4-fresh, often refrigerated) condition; T3/T851 tolerate only large-radius bends and will crack in tight bends.
What surface finishes work on 2024?
Chromic-acid or hard anodize plus primer is normal practice; expect darker, less uniform anodize colour than 6000 series, and use Alclad or conversion coating (Alodine) where corrosion exposure is expected.
2024 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 | ≤ 0.5 | 0.15 |
| Fe | ≤ 0.5 | 0.2 |
| Cuprincipal strengthening addition | 3.8 – 4.9 | 4.4 |
| Mn | 0.3 – 0.9 | 0.6 |
| Mg | 1.2 – 1.8 | 1.5 |
| Cr | ≤ 0.1 | 0.02 |
| Zn | ≤ 0.25 | 0.05 |
| Ti | ≤ 0.15 | 0.03 |
| Other (each)each | ≤ 0.05 | — |
| Other (total)total | ≤ 0.15 | — |
| Al | balance | — |
2024-T72 — frequently asked
What is 2024-T72 used for?
2024-T72 is typically used for aircraft skins and fuselage panels, wing and fuselage structural members, aerospace fittings and brackets, high-strength rivets and fasteners, tooling and jig plate and machined structural components. In short: high fatigue resistance; aerospace.
What is the yield strength of 2024-T72?
2024-T72 has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 83% of aluminum grades. Strength varies by condition: see the 18 listed tempers.
Is 2024-T72 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Excellent chip formation in T3/T351/T851 — high speeds, sharp positive-rake carbide tools and flood coolant give good finishes; annealed material is gummy.
Can 2024-T72 be welded?
Not readily — weldability is rated poor (20/100). Not suitable for fusion (arc) welding due to hot cracking; join by riveting, bolting, adhesive bonding, resistance spot welding or friction stir welding.
What surface finishes work on 2024-T72?
Chromic-acid or hard anodize plus primer is normal practice; expect darker, less uniform anodize colour than 6000 series, and use Alclad or conversion coating (Alodine) where corrosion exposure is expected.
Can 2024-T72 be formed, bent or molded?
Form in O or freshly solution-treated (T4-fresh, often refrigerated) condition; T3/T851 tolerate only large-radius bends and will crack in tight bends.
What is the maximum service temperature of 2024-T72?
2024-T72 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 2024-T3 and 2024-O?
T3 is the default condition — the standard aerospace sheet condition: best combination of strength, fatigue life and damage tolerance; most widely stocked. O: softest, most formable condition — pick it for severe forming/deep drawing, then solution treat and age to T4/T6. Yield strength is 345 MPa in T3 versus 75 MPa in O.
Can FabDigit make parts in 2024-T72?
Yes — 2024-T72 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B209 / B211 / B221 (Al sheet, plate, bar, extrusions) — ASTM International (2021)
- International Alloy Designations and Chemical Composition Limits (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS-17 Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- GB/T 3190 / GB/T 3880 (2A12, LY12 ) — SAC (2020)
- EN 573-3 / EN 485-2 (EN AW-2024) — CEN (2019)
- Constellium / Kaiser 2024 aerospace plate & sheet data — Constellium; Kaiser Aluminum (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.