2024-T3 aluminum
Specifying and processing 2024-T3 sheet with explicit bare/clad, thickness, test and final-condition boundaries.
Tags: materials, aluminum, heat-treatable, sheet-metal
On this page
Identify the complete material condition
Kaiser's historical Table 7.2 lists 63 ksi tensile and 42 ksi yield minima for bare 2024-T3 sheet at 0.021–0.128 in, versus 61 ksi tensile and 40 ksi yield for conventional Alclad T3 sheet at 0.063–0.128 in. Use the applicable current order, test direction, and footnotes for acceptance. Kaiser historical sheet limits
2024-T3 combines an alloy designation with a temper. The Aluminum Association registers 2024 as a wrought aluminum alloy with 3.8–4.9% copper, 1.2–1.8% magnesium and 0.30–0.90% manganese by mass. Those composition ranges do not specify a product's strength, cladding or dimensions. Retain the product form, complete temper and governing specification with the alloy name. Aluminum Association Teal Sheets, December 2025
The Australian Aluminium Council's Rolled Products Manual, January 2024, explains T3 as solution treatment or cooling from elevated-temperature shaping, followed by cold work and natural ageing to a substantially stable condition. It distinguishes T4, in which the corresponding strengthening cold work is absent or not recognized in the specification. T3 is a processing condition, not a generic synonym for heat-treated aluminum. AAC temper definitions, pp. 10–11
Keep T3 and T351 separate. Kaiser's flat-rolled reference lists T3 sheet and T351 plate in distinct entries. Do not shorten the latter to T3 or assume a supplier's “2024 plate” label establishes either condition. Match the purchased form and complete designation to the drawing and certificate. Kaiser flat-rolled product reference
Bare and Alclad sheet are different products
Kaiser's component table identifies conventional Alclad 2024 as a 2024 core with 1230 cladding. It separately lists one-side and reduced-cladding constructions. The clad metal is part of the composite sheet, not protective packaging or an anodized finish. Record which construction and sides the order requires. Kaiser Alclad component table
A drawing for bare stock is not automatically satisfied by clad stock of the same total thickness. Likewise, an Alclad callout cannot be replaced with bare stock merely by promising a later coating. Material properties, surface processing and corrosion protection need their own review. Preserve clad-side identity through cutting, forming and assembly; exposed edges and machined features require the protection specified for the finished part.
Read strength values with their scope
Kaiser's historical Table 7.2 distinguishes bare and Alclad T3 sheet. The following rows illustrate why one universal “2024-T3 strength” entry is inadequate:
| Product and specified thickness | Minimum ultimate strength | Minimum yield strength | Minimum elongation |
|---|---|---|---|
| Bare T3 sheet, 0.021–0.128 in | 63 ksi | 42 ksi | 15% |
| Conventional Alclad T3 sheet, 0.063–0.128 in | 61 ksi | 40 ksi | 15% |
These are bounded historical reference rows, not confirmation of the requirements for a current purchase. Consult the controlling specification, thickness band, specimen/test direction, gauge length and all table footnotes. They are neither typical values nor structural design allowables. The reference contains older specification information and expressly warns that its approval lists may not be current. Kaiser mechanical-property limits, Table 7.2 and specification notes
Original conversion example: using 1 ksi = 6.894757 MPa, 42 ksi is approximately 289.6 MPa, while 40 ksi is 275.8 MPa. The difference is about 13.8 MPa. This arithmetic compares the two cited rows; it does not authorize substituting a converted/rounded value for an ordered standard's original acceptance limit.
Forming, machining and thermal history
Qualify forming using the actual sheet gauge, temper, rolling direction, tool radius and surface requirement. Record cracks, springback, thinning and cladding damage where applicable. A successful annealed-stock trial does not qualify T3 stock, and a nominal bend radius without material direction is incomplete process information.
AAC treats annealing, solution treatment and ageing as distinct operations with time, temperature, thickness and quench conditions. Its typical heat-treatment tables are not instructions to heat a finished T3 part casually and continue calling it T3. If forming or joining introduces significant heat, assess the resulting material condition and required verification before release. AAC heat-treatment guidance, pp. 67–68
For machining, retain stock and grain orientation, clamping, operation order and final inspection conditions. Material removed from a clad face changes that surface construction; dimensional conformity alone does not establish that the required protection remains. Do not use a favorable machinability description as evidence of distortion-free thin walls or a universal cutting recipe.
Joining and service boundaries
Kaiser's 2024 technical sheets distinguish gas, arc and spot-welding ratings, with definitions that include crack sensitivity and loss of properties. Their comparative ratings do not establish a qualified welding procedure for T3 sheet. Assess the actual joint, final condition, heat-affected properties, protection and inspection requirements rather than assuming either unrestricted weldability or that no joining method is possible. Kaiser 2024 comparative joining characteristics and rating definitions
The same source's fatigue figures refer to a specified reversed-stress test. Such a value is not a life prediction for a riveted, scratched, corroded or variable-amplitude assembly. Use the applicable design basis and account for geometry, surface condition, environment and inspection. Cladding or a coating does not remove the need to evaluate exposed features and joints for their actual service.
Purchase and release record
Specify alloy/complete temper, sheet form, bare or defined clad construction, nominal size and tolerances, governing specification/edition, surface requirements and certification. Link the heat/lot identity to cut blanks and the accepted manufacturing route. Preserve the drawing revision, processing history, inspection method and measured final condition.
Where a substitution is proposed, compare the complete material and finished-part requirements before approval. Chemistry, an application label such as “aircraft sheet,” or one tensile number cannot stand in for that comparison.
Sources were reviewed November 1, 2026. Kaiser's two-page 2024 technical sheet is marked Rev. 05/06; the linked flat-rolled compilation contains section identifiers including KA-SP-FRP1-1.09. These historical references support the stated comparisons and are not represented as current specification revisions.