ASTM 6061 6063 3003 Aluminum Alloy Round Tube for Structural Applications

Aluminum Round Tube Overview

Aluminum round tube is a hollow circular section used wherever a light, rigid and corrosion resistant structural member is needed. The tube is produced by extrusion from aluminum alloy billet, and drawn tube is produced by pulling the extruded hollow through a die to bring the outside diameter, the wall thickness and the straightness of the section within tighter limits. The round section carries bending and torsion efficiently because the material is distributed away from the neutral axis.

Three alloys cover most requirements. 6061 is a heat treatable magnesium silicon alloy used where higher strength and good machining behaviour are needed. 6063 is the general purpose extrusion alloy, chosen for smooth surface finish and good formability. 3003 is a manganese alloy with excellent corrosion resistance and workability, often used for lower stress applications and for parts that are bent or formed after cutting.

Section Range and Form

The tube is supplied in a range of outside diameters and wall thicknesses so that the section can be matched to the load and the weight budget of the part. Thin wall tube keeps weight low for frames and trims, while thicker wall sections are used for load bearing members and for parts that are threaded or machined after cutting. Tube can be supplied in random lengths or cut to the exact length required for the assembly.

Where Round Tube Is Used

Typical uses include frame and support members, tent poles and pole repair sections, handrails, display and shelving frames, machine guards, and general fabrication work. In each case the round profile gives an even appearance from any angle, and the aluminum surface can be left mill finish, anodized or powder coated where a specific colour or extra surface hardness is wanted.

Because the material is aluminum, the finished part stays light compared with an equivalent steel tube and does not need painting to resist rust in normal indoor and outdoor service. Aluminum develops a thin natural oxide layer that protects the surface, and this layer can be thickened by anodizing when the part is exposed to weather or to cleaning chemicals.

Cutting, Machining and Inspection

Tube can be cut on a saw to square ends, deburred, drilled, tapped and bent to suit the assembly. Each batch is checked for outside diameter, wall thickness, length and straightness before packing, and the cut ends are inspected for burrs so that the tube is ready to fit without further preparation. Sections can be produced to the drawing or sample supplied by the customer.