6060 - AlMgSi0.5 Aluminium Pipes, Tubing & Tube (DIN, WNR)

Product Description

The aluminum alloy 6060, chemically designated as AlMgSi0.5 under the European Norms (EN) and historically known by the German system as Werkstoffnummer WNr 3.3206, is one of the most widely specified extrusion alloys in Europe.

Often grouped alongside its close relative 6063 (AlMg0.7Si / 3.32206), the 6060 alloy is engineered with a slightly lower magnesium and silicon content. This minor adjustment gives 6060 superior extrudability and exceptional suitability for complex, ultra-thin-walled hollow profiles, pipes, and precision tubing while maintaining robust corrosion resistance.

Global Standard Equivalents

When cross-referencing this material across international specifications, it corresponds to the following designations:

• Werkstoffnummer (WNr): 3.3206

• EN Chemical Name: EN AW-6060 / EN AW-AlMgSi

• Older DIN Standard: AlMgSi0.5 (DIN 1725-1)

• ISO Designation: AlMgSi

• AA (USA): 6060

• GOST (Russia): AD31 (АД31)

Manufacturing Standards & Tolerances

Pipes and tubes produced from 6060 / AlMgSi0.5 must adhere to stringent dimensional tolerances and testing methods, depending on how they are manufactured:

• EN 755-1 & 2: Dictates the general technical delivery conditions, inspection parameters, and required mechanical properties for all extruded structural tubes.

• EN 755-7: Governs the strict concentricity and wall-thickness tolerances for Seamless Extruded Tubes (critical for pressurized lines and uniform structural load distribution).

• EN 755-8: Governs tolerances for Porthole/Structural Tubes (machined with internal seam lines, preferred for framing and complex exterior geometries).

• EN 12020-2: Applies to ultra-high precision profiles where tolerances must be kept to a fraction of a millimeter for sliding or interlocking mechanisms.

Mechanical Properties by Temper

The technical capability of a 6060 pipe depends on its thermal heat-treatment temper. Below are the mandatory mechanical properties under EN 755-2 (for wall thicknesses $\le 5\text{ mm}$):

Fabrication & Material Characteristics

1. Complex Formability and Bending

In the T4 temper, 6060 is highly ductile. It can be bent into tight radii, flared, or hydroformed without cracking, making it excellent for intricate fluid loops. In the T6/T66 temper, the material is stiffer and less forgiving; tight bends risk wrinkling or fracturing the outer walls of the tubing unless specialized mandrel bending tools are utilized.

2. Anodizing Quality (AQC)

6060 / AlMgSi0.5 provides a cleaner, smoother surface finish straight out of the extrusion die than higher-strength alternatives. It reacts exceptionally well to both protective and decorative anodizing, yielding a uniform metallic or colored surface entirely free from structural streaking.

3. Weldability and Joint Strength

It is seamlessly weldable using conventional MIG and TIG processes, typically using 4043 (AlSi5) or 5356 (AlMg5) filler wire.

Technical Warning: The localized heat of the welding arc acts as an annealing process. This produces a Heat-Affected Zone (HAZ) surrounding the joint where the material's properties drop back down significantly toward the T4 state. If structural rigidity or internal pressure capacity is critical, the assembly must be re-aged post-weld, or the wall thickness must be increased at the connection points.

Common Applications for 6060 Tubing

• Pneumatic & Low-Pressure Systems: Air lines, light hydraulic returns, vacuum system tubes, and electrical shielding conduit.

• Architectural Structures: Balustrades, pedestrian safety railings, modular structural frames, window tracks, and interior furniture design.

• Thermal Systems: Heat exchanger tubes, heating manifolds, and specialized cooling channels, taking advantage of its excellent thermal conductivity ($\approx 200 \text{ W/m·K}$).

• Automotive Profiles: Interior trim skeletons, bus seat frames, and specialized structural framework components where light weight is highly prioritized.