# 2024-T351 aluminum

Product-specific reference for stretched 2024 aluminum, bare/clad distinctions, property selection and machining limits.

Reviewed: 2026-11-01

Tags: materials, aluminum, plate, heat-treatment

## Identify the alloy and full delivery condition

Kaiser's two-page 2024 technical sheet is explicitly marked **Rev. 05/06**. Its typical T4/T351 row gives **469 MPa ultimate tensile strength, 324 MPa yield strength and 19% elongation over 4D**, based on a 0.500-inch-diameter tensile specimen. These are representative reference values, not a minimum strength guarantee for every plate thickness or direction. [Kaiser typical mechanical properties, p. 1](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1012/Kaiser_Aluminum_2024_Sheet_Coil_and_Plate.pdf)

**2024-T351** identifies an aluminium alloy and its processing condition, not a complete purchase specification. Record the product form, bare or clad condition, original stock thickness, dimensions, governing specification and edition, inspection requirements and material certificate. Kaiser lists 2024-T351 among aerospace plate products, while also listing other 2024 tempers and extruded forms for different applications. These are distinct products, not interchangeable catalog descriptions. [Kaiser aerospace products](https://www.kaiseraluminum.com/end-markets/aerospace-and-high-strength/)

2024 is a copper-magnesium-bearing wrought alloy. Kaiser's technical sheet gives composition ranges of **3.8–4.9% copper, 1.2–1.8% magnesium and 0.30–0.9% manganese by mass**, with other element limits. A composition range defines the alloy envelope; it is not the actual analysis of a delivered lot. [Kaiser 2024 sheet/coil/plate technical data, Rev. 05/06, p. 2](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1012/Kaiser_Aluminum_2024_Sheet_Coil_and_Plate.pdf)

## T3, T351 and T3511 are different callouts

**T3** denotes solution heat treatment, cold work and natural ageing. **T351** adds a specific stress-relief treatment by controlled stretching; products receive no further straightening after stretching. The designation applies to forms including plate and rolled or cold-finished rod/bar. **T3511** belongs to the related stretched-product designation for extruded products and permits minor straightening after stretching to meet tolerances. Do not shorten T3511 to T351 in a material record. [Capalex temper definitions](https://capalex.co.uk/whatwedo/heat-treatment)

The practical distinction is the documented processing history and its applicable product requirements. A T3 sheet cannot be substituted for a T351 plate solely because a general property table groups related tempers together. Likewise, an extrusion must be assessed using its own product specification rather than a rolled-plate table.

Stress relief is not a promise of zero residual stress or a guarantee that a heavily machined part will remain flat. Set stock allowance, clamping and the machining sequence for the actual geometry. Check dimensions after releasing the workpiece from the fixture and after the final material-removal operation.

## Keep typical data, minima and allowables separate

A property selection should preserve the following distinctions:

| Data category | Appropriate use | Required qualification |
| --- | --- | --- |
| Typical supplier property | Preliminary comparison or estimation | Product, temper and test conditions |
| Specification minimum | Purchase acceptance | Applicable edition, thickness range, specimen and direction |
| Design allowable | Structural assessment | Approved data source, statistical basis, product scope and load case |

Kaiser's flat-rolled reference separates bare 2024-T351 plate from Alclad variants and splits mechanical-property limits into thickness ranges. Read the table headings and footnotes together; a value taken from a thin bare product cannot be assigned to thick clad stock. For a cut blank, retain the original plate identity and thickness rather than selecting properties solely from its final machined thickness. [Kaiser flat-rolled products, mechanical-property tables](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1010/Kaiser_Aluminum_Sheet_Plate.pdf)

Preserve longitudinal, long-transverse and short-transverse orientation where the specification or design data uses it. Record rolling direction through cutting and nesting so that the finished part can be related to the required material direction. A tensile certificate from one orientation is not evidence of every through-thickness property.

For aerospace design, the FAA identifies MMPDS as a source of statistically based metallic design allowables recognized within its limitations. Supplier typical values are not substitutes for the applicable approved data and design process. [FAA technical library, MMPDS description](https://www.faa.gov/data_research/library)

## Bare versus clad stock

Specify whether the product is bare, clad on both sides or clad on one side, including the applicable cladding requirement. Kaiser's flat-rolled reference treats these as separate entries. Do not interpret the strength or surface condition of a clad composite as identical to bare 2024. [Kaiser bare and Alclad product tables](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1010/Kaiser_Aluminum_Sheet_Plate.pdf)

Machining a pocket, facing a sheet or drilling an edge can change which material is exposed. Where surface protection matters, assess the final geometry and coating coverage rather than relying on the incoming-stock description. Preserve any required identification of clad surfaces during manufacture.

## Machining, joining and service boundaries

2024 is used for machined parts, but a favourable machinability description supplies no universal speed, feed or tool-life claim. Validate the actual stock, tool, coolant and cutting strategy against dimensional and surface requirements. Thin walls, asymmetric pockets and extensive stock removal deserve a stability trial, even with stretched material.

Smiths describes its **AMS-QQ-A-225/6 2024** drawn/rolled/cold-finished product as T351, with good machinability, poor atmospheric corrosion resistance and joining restrictions: resistance, spot and beam methods are described favourably, while other welding methods are not recommended. This supplier statement is product-specific and is not a qualified welding procedure for an arbitrary plate assembly. [Smiths 2024 T351 product guidance](https://www.smithmetal.com/ams-qqa-225-6-2024.htm)

Qualify any joining or thermal process for its effect on the delivered condition, local properties, distortion and corrosion protection. Do not assume that properties remain those of the original T351 certificate after welding or another significant heat treatment.

For corrosion-sensitive service, specify the complete protection and assembly arrangement: surface preparation, coating or cladding, coverage at machined features, contact with other materials and inspection criteria. An anodised sample or an aerospace application listing does not establish suitability for an unspecified environment or fatigue life.

## Related reference

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