Steel Tubing Sizes: A Practical Guide to Dimensions and Applications

Steel tubes can be found in all sorts of places if you take the time to look, from road bridges to garden furniture, its versatility is virtually unparalleled in the world of fabrication.

To effectively use tubing in your projects, it helps to understand the different types and sizes, as well as each one’s advantages. This guide will explain all of the key things you need to know.

What Steel Tubing Is Used For Across Industries

Thanks to steel tubing’s light weight, simple geometry, and low cost, it is used for a wide range of applications.

As a structural section, it can be found in large structures such as shopping malls or bridges. It is commonly used for framework and bracketry in all sorts of consumer products too, such as sports equipment and hand tools.

Another key use of tubing is to transport fluids such as oil, gas, water, and air. It is often used in conjunction with welding on flanges, gaskets, and seals to create systems capable of containing high pressures.

Common Steel Tubing Sizes and Shape Variations

Round tubing is available in many sizes ranging from 0.375” up to 24” in diameter.

However, tubing is not just round, it is also supplied in square and rectangular form factors. Typically, these square tubes are used predominantly for structural/fabrication purposes rather than carrying fluids.

Square tubing is very useful for welded frameworks as it requires less preparation before making angled joints, and it also enables easier mounting of plates, brackets and other components to the flat sides.

Square and rectangular tubing is readily available in sizes ranging from 0.375” up to 12” wide.

Wall Thickness, Gauge, and Strength Explained

Wall thickness, or gauge, is an important factor in the strength of a tube. Often, the tube is specified by gauge or “wall thickness” rather than the “schedule” often used when discussing pipe.

This is because the tube is more often used for structural applications where the key ID and OD measurements are vital, rather than its pressure-carrying capacity, as with pipe.

In general, the thicker the wall, the stronger the tube. But this comes with some considerations, such as the materials’ own weight, and whether a large but thinner tube would be preferable.

Metric vs Imperial Steel Tubing Sizes

Tubing is used all over the world, and as such is made in both metric and imperial designations. In some markets, certain sizes will be made using the same tooling, eg, 1” tubing may measure 25mm or vice versa.

Other than the outside sizing and its labeling, metric tubes don’t differ much from imperial sizes. With the high quantity of sizes being available, it’s unlikely to be unable to find a size that suits your requirements.

Choosing the Right Steel Tubing Size for Your Application

If you are designing or making fabricated parts, for which steel tubing is to be used, it’s important to make sure you select the correct size, thickness and shape.

• Strength: Making sure the material is strong enough for the forces involved is crucial. If large loadings are involved, consider both thick-walled, smaller outside diameter tubes, as well as larger, but thinner sections. The latter may require more physical space but could end up weighing less.
• Ease of manufacturing: In general fabrication, square or rectangular tubing is often easier to work with, as it provides a natural flat face to mount and join to.
• Cost: Tubing is a relatively inexpensive material, but it is more expensive than rolled sections such as angles, beams, or channels, in larger diameters. Consider these for the most cost-effective solutions for large structures.

Get Your Tubing From Metal Supermarkets

If you need round, square, or rectangular tubing, check out the wide range on offer from Metal Supermarkets. In addition to a wide range of sizes, thicknesses, and materials, a cutting service is available, along with nationwide delivery.

Find your nearest store here, or browse the range of tubing here.