How Extruded Aluminum Tubes Are Made
Aluminum tubes are produced by extrusion, a process in which a heated aluminum billet is forced through a shaped die under high pressure. The metal emerges in a continuous profile with the cross-section of the die opening, and the hollow tubular shapes are formed either with a mandrel in the die or by piercing the billet before extrusion. Because the whole length of the tube shares one cross-section, extrusion gives uniform wall thickness, straightness and surface quality at high production rates. Tubes can then be cut to length, machined and surface-finished, and the process supports round, square, rectangular and fully custom shapes in a single operation.
Alloy and Temper: Why 6063-T5
6063 is the classic architectural extrusion alloy, combining magnesium and silicon so that it responds well to heat treatment and anodizing. The T5 temper is produced by cooling the extrusion from the press and then artificially aging it, which raises strength without a separate solution treatment. In this condition 6063 offers a typical minimum tensile strength of about 145 MPa with good ductility, which is sufficient for windows, doors, handrails, frames and many industrial tubes while keeping the metal easy to bend and machine. For more demanding loads, 6061-T6 or a thicker wall can be specified, but 6063-T5 remains the economical default where surface quality and formability matter more than maximum strength.
Surface Treatment and Finish Options
The natural finish after extrusion is a mill finish, which is fine for concealed applications. Where appearance and protection are required, anodizing builds a hard, transparent or colored oxide film on the surface, available in silver, bronze, black, gold, blue and gray, and it is the preferred finish for architectural tubes because it does not peel or fade like paint. Powder coating offers a wider color range with good impact resistance, and electrophoresis combines a paint-like film with excellent uniformity. For brighter decorative parts, mechanical or chemical polishing is applied before anodizing. The finish should be specified together with the alloy, because the anodizing result depends on the metal quality and the preparation of the surface.
Dimensions, Machining and Custom Options
6063-T5 tubes are supplied with wall thickness commonly from 0.8 mm to 5.0 mm, and diameters, widths or profile shapes per the customer drawing, with a typical dimensional tolerance of about 1 percent or per agreement. Lengths are cut to order, and secondary machining such as cutting, punching, drilling, tapping and milling can be completed before delivery so the customer receives ready-to-assemble parts. Because extrusion dies are built to the required cross-section, custom profiles avoid the welding or assembly needed to build the same shape from standard tubes. For projects that are still in design, the extrusion can be re-designed or developed from a sketch, and samples can be produced for validation.
Applications in Architecture and Industry
Architectural tubes carry a large share of the demand: aluminium windows and doors, curtain wall mullions, louvers, wardrobes, handrails, formwork and greenhouse frames all use extruded tube because it combines light weight, corrosion resistance and clean appearance with easy installation. Industrial applications include aluminum heat sinks, flat bars, and square, round or rectangular tubes for equipment frames, machine guarding, conveyors and electronic communication structures. In transport, tubes serve railings, luggage racks and trim, and in electrical and electronic fields they act as housings and structural members where non-magnetic, corrosion-resistant material is required. The same tube can therefore move from a decorative handrail to a load-bearing frame simply by specifying the right alloy, temper, wall and finish.
FAQ
What is 6063-T5 aluminum tube used for?
It is used for windows and doors, curtain walls, louvers, handrails, wardrobes, greenhouse frames, heat sinks and general industrial tubing.
Why is 6063 preferred for anodizing?
6063 has a low content of elements that discolor the film, so it produces bright, uniform anodic finishes in silver, bronze, black, gold, blue and other colors.
What is the difference between T5 and T6 temper?
T5 is cooled from the press and artificially aged, giving moderate strength with excellent surface quality; T6 undergoes solution treatment before aging and offers higher strength.
Can extruded tubes be made in custom shapes?
Yes. Extrusion dies are built to the required cross-section, so round, square, rectangular and fully custom tubular profiles can be produced to drawing.
What wall thickness is typical for 6063-T5 tubes?
Wall thickness is commonly supplied from 0.8 mm to 5.0 mm, with the choice driven by the load, the profile size and the finishing process.