# 7075 aluminum

Selecting 7075 aluminum by product form, temper, strength basis, corrosion exposure and manufacturing route.

Reviewed: 2026-11-01

Tags: materials, aluminum, heat-treatment

GLEICH's **ALPLAN 7075** is T651 rolled plate, precision milled on both sides and film protected. Its **12–40 mm** stock range has **±0.10 mm thickness tolerance** and thickness-dependent flatness. A 20.00 mm plate gives a thickness interval of **19.90–20.10 mm**. Mechanical values are typical at room temperature, and temperature entries concern strength after cooling. [GLEICH ALPLAN 7075, 18 October 2023](https://gleich.de/wp-content/uploads/2023/11/Data-Sheet-ALPLAN%C2%AE-7075-1.pdf)

7075 is a heat-treatable aluminum alloy used where high strength is valuable. The alloy number alone does not specify a usable engineering material: plate, extruded bar and cold-drawn bar can have different property requirements, while aging condition changes the balance between strength and resistance to stress-corrosion cracking. Specify the complete product and temper before assigning a design value.

## Identity and ordering language

The Aluminum Association's **December 2025** registration record identifies 7075 as an aluminum-zinc-magnesium-copper alloy. Registered composition limits include zinc 5.1–6.1%, magnesium 2.1–2.9%, copper 1.2–2.0% and chromium 0.18–0.28%, by mass. These are composition ranges, not a recipe for predicting a finished part's strength. Chemistry compliance does not establish temper, dimensional quality or mechanical-property compliance. [Aluminum Association, International Alloy Designations and Chemical Composition Limits](https://www.aluminum.org/sites/default/files/2026-01/Teal%20Sheets%20December%202025.pdf)

A useful purchase description identifies alloy, full temper, product form, dimensions, applicable product specification and revision, and required inspection documentation. Add grain orientation, surface condition, flatness, machining allowance and corrosion protection when these affect the part. If a drawing requires clad material, make the cladding requirement explicit rather than assuming that every 7075 sheet or plate has the same surface construction.

## Temper is a material requirement

T6 denotes solution heat treatment followed by artificial aging. T7 denotes solution heat treatment followed by stabilization beyond the maximum-strength condition to control a particular characteristic. Therefore, substituting a T7-family condition for T6 requires checking the specified properties, not simply accepting another heat-treated 7075 stock item. Preserve suffixes such as **T651, T7351 or T73511** when requesting stock; they are part of the material designation. The Australian Aluminium Council's rolled-products manual carries a **January 2024** page header, despite its February filename. [AAC, Rolled Products Manual, temper definitions](https://aluminium.org.au/wp-content/uploads/2024/02/Rolled-Products-Manual-Final-Version-Feb24.pdf)

The practical strength–corrosion tradeoff appears in Kaiser's historical sheet, coil and plate data. Its **Rev. 05/06** table gives these **typical**, rather than guaranteed minimum, properties:

| Temper | Ultimate tensile strength | Yield strength | Elongation |
| --- | ---: | ---: | ---: |
| T651 | 572 MPa | 503 MPa | 11% |
| T7351 | 503 MPa | 434 MPa | 13% |

The tensile-property table specifies a 0.500-inch-diameter specimen and elongation over four specimen diameters. Kaiser's comparative stress-corrosion rating improves from C for T651 to B for T7351, while its general-corrosion rating remains C for both. This supports a particular tradeoff; it does not establish immunity in every orientation, environment or residual-stress state. The manufacturer's ratings use specified exposure/testing bases and service experience. These historical typical values are unsuitable as automatic drawing acceptance limits or current structural design allowables. [Kaiser, 7075 Sheet, Coil and Plate](https://online.kaiseraluminum.com/depot/PublicProductInformation/Document/1017/Kaiser_Aluminum_7075_Sheet_Coil_and_Plate.pdf)

## Product form changes the property basis

Constellium's undated 7075 material sheet separates **minimum EN mechanical values** from **typical hardness**. For its listed cold-drawn bar dimension **D ≤ 80 mm**, the rows include:

| Cold-drawn condition | Minimum yield strength Rp0.2 | Minimum tensile strength Rm | Minimum elongation A |
| --- | ---: | ---: | ---: |
| T6 | 485 MPa | 540 MPa | 7% |
| T7351 | 385 MPa | 455 MPa | 8% |

The same sheet lists separate extruded-bar rows with different dimensional intervals. Do not extend these cold-drawn values to plate, to a larger section, or to a different manufacturing route. Its hardness column also has a different statistical basis from the minimum tensile columns. When comparing suppliers, match form, dimension interval, temper and test basis before comparing numbers. Confirm the governing standard and certificate for the delivered item. [Constellium Extrusions Děčín, 7075 material sheet](https://assets.ctfassets.net/e62qtriulv4v/6e4GZoAaAvKj3SWe6BPF1E/2f062657e0c1fa9ca918f269576ef857/Material_sheet_7075.pdf)

## Forming, machining and joining

Plan the manufacturing sequence around the delivered condition. The AAC manual's cold-bending guidance distinguishes 7075-O from 7075-T6 and changes recommended bend geometry with thickness. A bend radius taken from another temper is not a general 7075 rule. For a tight bend, establish the required starting condition, forming trials and any subsequent heat-treatment qualification before ordering hardened stock. Its brazing guidance also identifies 7075 as unsuitable for conventional brazing because of its low melting range relative to the process. [AAC, Rolled Products Manual, bending and brazing guidance](https://aluminium.org.au/wp-content/uploads/2024/02/Rolled-Products-Manual-Final-Version-Feb24.pdf)

For machining, specify the final datum scheme and inspect after the operations that release or redistribute stock stresses. A supplier's incoming flatness tolerance cannot guarantee the shape of a thin wall after extensive material removal. Thermal stress-relief or finishing operations likewise need approval against the required final temper and properties.

ESAB's **21 July 2021** guidance treats 7075 as generally unsuitable for ordinary arc welding. It explains that an initially sound-looking joint can subsequently develop stress-corrosion cracking associated with the weld's thermal effects, stress and environment. Consequently, neither an attractive bead nor a successful short-term pull test establishes a suitable repair. A specialized joining route needs its own material, process and acceptance qualification; this restriction on conventional arc welding does not mean every possible joining technology is identical. [ESAB, How do I weld 2024 and 7075?](https://esab.com/us/nam_en/esab-university/blogs/how-do-i-weld-2024-and-7075/)

## Selection and service limits

Choose the temper against the actual failure modes: yielding, fatigue, fracture, stress-corrosion cracking, wear and dimensional instability are different questions. A tensile-strength value alone cannot resolve a fatigue-loaded or corrosive application. Treat temperature, exposure duration, load direction and protective finish as inputs to the material assessment.

For a useful engineering record, retain the product certificate and identify which values are specification minima, supplier typical data or approved design allowables. Record the final temper after processing, inspect critical surfaces and dimensions, and define the corrosion-protection system. If substitution is proposed, compare the complete material condition and product requirements; matching the number **7075** is only the first check.

## Related reference

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