# 2024 aluminum

Composition, bare versus clad stock, temper and product-form property limits, forming, corrosion, fatigue, and joining boundaries for 2024 aluminum.

Reviewed: 2026-11-01

Tags: materials, aluminum, heat-treatable, aluminum-copper

## Identity and material state

Kaiser's conventional two-side Alclad 2024 construction uses **1230 cladding**, nominally **5% per side through 0.062 inch**. At **0.040 inch** total thickness, that means **0.002 inch nominal cladding on each side** and **0.036 inch nominal core**. The arithmetic describes the listed construction. Actual clad thickness requires evidence for the product. [Kaiser Alclad component table](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1010/Kaiser_Aluminum_Sheet___Plate.pdf)

2024 is a wrought aluminum-copper-magnesium alloy designation. The Aluminum Association's **August 2018 Teal Sheets** register **3.8–4.9% copper, 1.2–1.8% magnesium, and 0.30–0.90% manganese**, with aluminum as the remainder and limits on other elements. These are composition ranges by mass, not a particular producer's measured chemistry. Alloy identity alone does not identify temper, product form, cladding, thickness, or design strength. [Aluminum Association registration record](https://www.aluminum.org/sites/default/files/2021-10/Teal%20Sheet.pdf)

## Temper and processing history

The Metals Service Center Institute identifies **T3** with solution heat treatment and cold work, **T4** with solution heat treatment, and **T6** with solution heat treatment plus artificial aging. These labels describe processing conditions, not an ascending quality scale. Retain all digits: a stress-relieved variant should not be collapsed into its shorter base temper. [MSCI T-temper overview](https://www.msci.org/topic/numbers-following-t/)

2024 is precipitation hardenable. ESAB explains that solution treatment, quenching, and aging establish the strengthening condition, and that thermal exposure can change it. Its **September 19, 2024** guidance also explains why a welded heat-affected zone can differ substantially from unaffected stock. A generic furnace temperature cannot establish a final temper: use the applicable heat-treatment procedure, product requirements, and verification. [ESAB strengthening and thermal-exposure guidance](https://esab.com/us/nam_en/esab-university/articles/discover-how-arc-welding-affects-the-haz-of-the-weld/)

Specify the state in which a part is formed, machined, inspected, and delivered. If processing changes that state, acceptance must address the final part rather than relying solely on the incoming certificate. A material substitution or extra thermal cycle needs review for properties, distortion, and surface protection.

## Bare and clad products

Kaiser's flat-rolled reference distinguishes a **2024 core with 1230 cladding**, two-side clad products, one-side clad products, and reduced-cladding variants. Its component table, bearing code **KA-SP-FRP1-1.09**, gives nominal cladding per side of **5% of composite thickness through 0.062 inch** and **2.5% from 0.063 inch upward** for the listed conventional two-side Alclad 2024 product. Other variants have different entries. Cladding is bonded metal, not a removable shipping film or an anodic coating. [Kaiser flat-rolled reference, components of heat-treat Alclad sheet and plate](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1010/Kaiser_Aluminum_Sheet___Plate.pdf)

Keep clad/bare identity and the clad side with the part traveler. Machined faces, holes, and cut edges need their specified protection; do not assume a clad face establishes corrosion performance for the entire finished assembly.

## Typical properties versus specification limits

Kaiser's **Sheet Coil & Plate Alloy 2024**, marked **Rev. 05/06**, labels its mechanical table **typical** and identifies a 0.500-inch-diameter tensile specimen with elongation over 4D. Selected rows show the strength/ductility tradeoff. They are not thickness-specific guaranteed minima for arbitrary sheet or plate. [Kaiser 2024 typical mechanical properties](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1012/Kaiser_Aluminum_2024_Sheet_Coil_and_Plate.pdf)

| Listed temper | Typical ultimate tensile strength | Typical yield strength | Typical elongation/4D |
| --- | --- | --- | --- |
| O | 186 MPa | 76 MPa | 22% |
| T4, T351 | 469 MPa | 324 MPa | 19% |
| T361 | 496 MPa | 393 MPa | 13% |

By contrast, Kaiser's historical mechanical-limit table separates thickness rows. Its **bare T3 sheet** rows list minimum ultimate strength of **63 ksi at 0.021–0.128 inch** and **64 ksi at 0.129–0.249 inch**, with **42 ksi minimum yield** and **15% minimum elongation** in those rows. This is a bounded illustration of thickness-dependent requirements from that reference, not confirmation of a current order's limits. Read the controlling specification, test orientation, specimen basis, and footnotes. [Kaiser flat-rolled mechanical-property limits, Table 7.2](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1010/Kaiser_Aluminum_Sheet___Plate.pdf)

For procurement, match alloy, complete temper, form, thickness range, clad condition, specification revision, and test direction before comparing a certificate with a requirement. A typical 469 MPa value cannot replace the applicable minimum, and a bar specimen result cannot establish every plate orientation.

## Forming and machining

Kaiser offers the named **2024-T4 T-FORM** sheet product for bending, joggling, stretch forming, and hydroforming, describing improved formability compared with conventional T3/T4 while retaining properties equivalent to standard T4. Its public two-page flyer does not display a revision date. Those are product-specific claims; they do not describe every supplier's 2024-T4 stock. [Kaiser T-FORM product flyer](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1020/Kasier_Aluminum_2024-T4_T-FORM.pdf)

Choose forming trials for the actual gauge, temper, rolling direction, tool radius, and required surface condition. Check cracks, springback, and cladding damage as applicable. For machining, retain grain orientation and a dimensional inspection plan; incoming mechanical properties do not prove the finished part will remain within tolerance after material removal.

## Corrosion, fatigue, and joining

Kaiser's rod-and-bar reference, coded **KA-RBH-2024-8.10**, rates general corrosion resistance D for its listed strengthened tempers and differentiates stress-corrosion ratings by temper. The ratings are comparative and tied to stated exposure/test conditions. Use them to flag protection and environment review, not as a universal corrosion rate or chemical-compatibility guarantee. [Kaiser 2024 rod and bar comparative characteristics](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1022/Kaiser_Aluminum_2024_Rod_and_Bar.pdf)

The sheet/plate table's fatigue column is explicitly **R.R. Moore-type reversed-stress testing** with a stated cycle condition. Such a result is not a fatigue-life allowance for a notched, riveted, corroded, or variable-amplitude component. Match the fatigue assessment to stress ratio, surface, orientation, environment, geometry, and load history; strength alone does not establish crack-growth or inspection requirements. [Kaiser fatigue-test context](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1012/Kaiser_Aluminum_2024_Sheet_Coil_and_Plate.pdf)

Avoid both “readily weldable” and an unqualified “cannot be joined.” Kaiser's rod/bar table distinguishes gas, arc, and spot welding and gives some conditions ratings requiring special techniques or preliminary trials. A general rating does not establish an acceptable repair procedure. Evaluate the joint process, crack sensitivity, HAZ properties, corrosion protection, and inspection against the actual design. Mechanical fastening or bonding also requires its own joint and surface-preparation qualification. [Kaiser joining ratings and definitions](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1022/Kaiser_Aluminum_2024_Rod_and_Bar.pdf)

## Related reference

[Grades, tempers, and conditions](../grades-tempers-and-conditions.md)