# 7075-T6 aluminum

7075-T6 alloy and temper identity, form-dependent property evidence, stress corrosion and fabrication limits.

Reviewed: 2026-10-29

Tags: materials, aluminum, tempers, heat-treatment

## Identity and temper

Alcoa's historical 7075-T6 sheet data give **74 to 78 ksi minimum long-transverse tensile strength** for **bare sheet at 0.008 to 0.249 in**, with minima varying by gauge. Its separate **two-side Alclad** entries span **68 to 76 ksi**. Use the ordered thickness, clad construction and test direction to select a row. [Alcoa Mill Products, pp. 2–3](https://www.voestalpine.com/highperformancemetals/usa/app/uploads/sites/294/2025/11/alloy7075techsheet.pdf)

7075 is a wrought aluminum alloy containing zinc, magnesium and copper. Kaiser's composition limits include 5.1 to 6.1% zinc, 2.1 to 2.9% magnesium and 1.2 to 2.0% copper by mass. These are composition ranges, not temper-dependent strength values. [Kaiser Aluminum, sheet, coil and plate technical data, revision 05/06, page 2](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1017/Kaiser_Aluminum_7075_Sheet_Coil_and_Plate.pdf)

The suffix describes treatment. Alcoa defines T6 as solution heat treatment followed by artificial aging. Alcoa limits this definition to products without cold work after solution treatment, or products whose flattening or straightening cold work may not be reflected in mechanical properties. T651 additionally identifies stress relief by stretching. T73 and T7351 describe overaging beyond maximum strength to control other characteristics. The same document identifies T7351 as having better stress-corrosion resistance than T6 and T651. These conditions belong to one alloy but represent different property balances. [Alcoa Global Cold Finished Products, Alloy 7075, May 2004, page 1](https://www.spacematdb.com/spacemat/manudatasheets/alcoa_alloy_7075.pdf)

## Product form and property basis

SAE AMS4045N, revised 21 September 2026, names T6 sheet and T651 plate. Its public scope covers thicknesses of 0.008 to 4.000 inches, inclusive. The accessible publisher summary does not provide the full acceptance requirements. [SAE AMS4045N, title and scope](https://saemobilus.sae.org/standards/ams4045n-aluminum-alloy-sheet-plate-56zn-25mg-16cu-023cr-7075-t6-sheet-t651-plate-solution-precipitation-heat-treated)

Selected producer data illustrate why a single universal strength number is incomplete.

| Product and condition | Basis | Selected values | Applicability |
| --- | --- | --- | --- |
| Alcoa bare T6 sheet | Minimum long-transverse properties | Tensile 74 to 78 ksi, yield 63 to 69 ksi | Published thickness span 0.008 to 0.249 in. The ranges summarize thickness-dependent minima. |
| Alcoa bare T651 plate | Minimum long-transverse properties | Tensile 78 to 67 ksi, yield 67 to 54 ksi | Published thickness span 0.250 to 4.000 in. Values decrease across the listed span. |
| Alcoa T6 cold-finished rod | Specified minima | Tensile 77 ksi, 0.2% offset yield 66 ksi, elongation 7% where testing is required | Through 4.000 in. section thickness, determined at the cross section used for the tensile specimen. Elongation basis is 2 in. or four specimen diameters. Elongation testing is not required when dimensions cannot yield a standard specimen or for shapes thinner than 0.062 in. |
| Kaiser T6 tube and pipe | Typical properties | Tensile 83 ksi / 572 MPa, yield 73 ksi / 503 MPa | Table identifies a 0.500 in. diameter tensile specimen and 11% elongation over four diameters. |

Sheet and plate rows come from [Alcoa Mill Products, Alloy 7075, document SPD-10-037, page 2](https://www.voestalpine.com/highperformancemetals/usa/app/uploads/sites/294/2025/11/alloy7075techsheet.pdf). The rod row includes the specimen-thickness basis and elongation-testing exceptions in [Alcoa's May 2004 cold-finished data, page 2, footnotes 2, 3 and 5](https://www.spacematdb.com/spacemat/manudatasheets/alcoa_alloy_7075.pdf). The tube row comes from [Kaiser's revision 05/06 tube and pipe data, page 1](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1042/Kaiser_Aluminum_7075_Tube_and_Pipe.pdf).

**Synthesis.** Typical values describe producer reference behavior. They are not guaranteed minima or design allowables. A range covering several thicknesses does not identify the required minimum at an arbitrary intermediate thickness. Sheet and plate values do not establish extrusion, forging or tube properties. A source minimum also does not establish that an unidentified lot meets its specification.

## Stress corrosion and joining

Kaiser's tube reference rates T6 stress-corrosion resistance C and T73 B. The ratings use service experience and 3.5% sodium-chloride alternate-immersion tests. C includes service failures under sustained short-transverse tension and limited long-transverse laboratory failures. B means no known service failures, with limited short-transverse laboratory failures. Better relative resistance does not mean immunity. [Kaiser tube and pipe data, page 1, footnote 2](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1042/Kaiser_Aluminum_7075_Tube_and_Pipe.pdf)

That reference rates gas and arc welding D, meaning no commonly used methods had been developed within its rating system. Spot welding is B. This rating describes weldability with special techniques, or for specific applications where preliminary trials or testing are justified to establish the welding procedure and weld performance. The ratings distinguish joining processes. [Kaiser tube and pipe data, page 1, footnote 4](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1042/Kaiser_Aluminum_7075_Tube_and_Pipe.pdf)

Hydro likewise describes 7075 as a poor welding choice while allowing resistance welding. Its broader statement that 7075 resists stress cracking does not identify temper, stress direction or test conditions. The bounded Kaiser comparison above supplies those distinctions. Hydro also warns that the alloy may not be available at every location. [Hydro, 7075 Aluminum, undated product overview](https://www.hydro.com/us/us/aluminum/products/extruded-profiles/north-america-resources/extruded-aluminum-products/aluminum-extrusion-alloys/7075-aluminum/)

## Heat treatment and supported deductions

**Synthesis.** Because artificial aging distinguishes T6 and overaging distinguishes T73, thermal processing and the required final condition are linked. A supplied T6 designation alone does not prove the state after subsequent heating. The sources here do not establish a qualified solution-treatment, quench, aging or post-weld cycle for a particular part.

Kaiser gives a nominal density of 2.80 Mg/m³ at 20 °C. **Derived example.** For 100 cm³ of solid material at that density, mass is approximately 0.280 kg. This calculation excludes voids and does not determine stock allowance, machining loss or lot chemistry. [Kaiser sheet, coil and plate data, page 2](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1017/Kaiser_Aluminum_7075_Sheet_Coil_and_Plate.pdf)

**Synthesis.** A requirement stated only as "7075-T6" leaves product form, dimensions, cladding, test orientation and governing specification unresolved. Greater quoted tensile strength does not establish a substitute with equivalent stress-corrosion performance. Generic data establish neither customer processing capability nor acceptance of a particular substitution.

## Sources and coverage limits

Sources reviewed 29 October 2026 PDT. Kaiser's two-page sheets carry revision 05/06. Alcoa's cold-finished sheet carries © 5/04 and is available through a third-party archive. The four-page Alcoa Mill Products brochure carries SPD-10-037 without a verified publication date and is hosted by voestalpine. These are historical producer references, not current supply commitments. SAE's indexed public publisher text establishes the named revision and scope only. Direct retrieval of that page timed out during this audit. Its paywalled requirements were not inspected.

The public PDF text was inspected. Kaiser's sheet-and-plate extraction omitted page 1, so this article uses only its page 2 composition and density. The tube document supplied both pages. No universal fatigue limit, allowable service temperature, heat-treatment schedule or finished-part performance is established here.

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