The short answer: Round bar is solid metal. Tube is hollow. Choose based on the finished part’s design, the material you need to remove or join, and the dimensions shown on your drawing.

It sounds simple, but ordering “25 mm stainless” without saying whether you mean bar or tube can lead to the wrong material arriving. Here’s what to check before you order.

What is round bar?

Round bar, also called rod by many buyers, is solid stock with a circular cross-section. It is commonly used as the starting material for turned parts, pins, spacers, shafts and other machined components.

Round bar is generally specified by material, grade, diameter and length. For example:

316 stainless steel round bar, 20 mm diameter, cut to 300 mm long.

Explore our round bar range.

What is tube?

Round tube has an outside diameter and a hollow centre. It is used for fabricated assemblies, sleeves, frames, rails and other parts designed around a hollow section.

Tube needs more information than a single diameter. Specify the outside diameter, wall thickness and cut length, as well as the material and grade. Two tubes can have the same outside diameter but very different wall thicknesses and inside diameters.

Explore our metal tube range.

How do you choose?

Start with the drawing or the finished part:

These are starting points, not engineering specifications. Loading, joining method and the operating environment can affect material selection.

What should you measure before ordering?

For round bar, check the diameter and required cut length.

For tube, check the outside diameter and wall thickness. If the inside diameter is critical, say so: nominal tube dimensions and manufacturing tolerances may affect the fit. Also specify any end preparation or cut tolerance your project requires.

Finally, confirm the material. Cut Length Metals supplies selected stainless steel, brass and aluminium products in cut lengths, but available profiles and grades vary across the range.

Get the right piece for the job

Whether you need one piece for a repair or repeated cuts for production, ordering the correct stock shape saves time at the bench. Cut Length Metals is based in Caboolture, Queensland, and ships orders across Australia.

Compare round bar and tube, or send us your measurements if you’re unsure how to specify the material.