7075-AlZnMgCu1.5 Aluminium Bar, Rod & Round Bars (ONORM)

Product Description

The designation 7075 / AlZnMgCu1.5 specifies one of the highest-strength aluminum alloys commercially available. When referenced alongside ÖNORM (the Austrian Institute for Standardization), it indicates cross-compliance between European standards (EN) and historic or localized Austrian material specifications for long products (bars, rods, and round bars).

Standard & Designation Cross-Reference

Historically, Austrian standardizations align seamlessly with broader European norms. The designation breaks down across international systems as follows:

• Chemical Designation (EN/ÖNORM): AlZnMgCu1.5

• Numerical Designation (EN/ÖNORM): EN AW-7075 (per EN 573-3)

• WNr. (Werkstoffnummer): 3.4365

• US Standard (AA/AISI): 7075

• Historic ÖNORM Equivalent: Typically covered under the older ÖNORM B 3000 series or current adoptions of European long-product standards (such as EN 755 for extruded bars and EN 754 for cold-drawn bars).

Chemical Composition (Weight %)

The "AlZnMgCu1.5" nomenclature highlights the primary alloying elements that give this 7000-series material its ultra-high strength via precipitation hardening:

Typical Mechanical Properties (T6 / T651 Temper)

For round bars and rods, the T6 (solution heat-treated and artificially aged) or T651 (stress-relieved by stretching) tempers are the industry defaults. Mechanical values can fluctuate slightly depending on the bar diameter (per EN 755-2):

Key Applications & Characteristics

• Machinability: Excellent when utilizing high-speed cutting tools. It produces tight, manageable chips rather than long, gummy ribbons common to softer aluminum grades.

• Corrosion Resistance: Moderate. Due to the high copper content, AlZnMgCu1.5 is susceptible to stress corrosion cracking and atmospheric weathering compared to the 5000 or 6000 series. Anodizing or defensive coatings are highly recommended for exposed components.

• Welding: Generally poor. It is considered a non-weldable alloy by conventional fusion methods due to micro-cracking and severe heat-affected zone (HAZ) softening.

• Primary Industries: Highly favored in aerospace structural frames, military ordnance, high-stress motorsport components, and heavy-duty clamping/fastening hardware.