Typical applications include: building construction, railings, and truck frames. The tubes are measured by their outside dimensions and their wall thickness.

Rectangular tubing is available in the following metal types:

• Aluminum
• Mild Steel
• Stainless Steel

Aluminum rectangular tubes are used in a variety of applications, such as structural, fencing and handrails due to their light weight and corrosion resistance. These come in several standard sizes but can be cut to custom lengths.

Steel rectangular tubing is a welded structural grade tube available in either A513 mechanical or A500 structural designations. This type of tube is a favorite for industrial maintenance, agricultural implements, transportation equipment and trailers. Given the right equipment and know-how, it is easy to weld, cut, form and machine.

There are three main methods for manufacturing tubing:

1. Seamless (can be produced through extrusion)
2. As-welded (or electric resistant welded [ERW])
3. Draw-over-mandrel (DOM)

Which process is used depends on the metal type. Aluminum tubing is either extruded or cold drawn.

Stainless tubing can be welded — roll-forming strips of stainless steel into a tube shape and then welded (same as hot rolled welded) — or seamless (through the extrusion process).