We do not recommend using either hot rolled steel or aluminum with our linear motion systems. Both of these materials lack the tolerances and dimensional stability present in cold rolled steel, which is typically +0 / -0.004" in critical dimensions, whereas aluminum and hot rolled steel can often be +/- 0.030" in the same dimensions.

In addition to tolerance issues, both of these materials are prone to dimensional changes over time. Hot rolled steel is typically coated in a "scale" that wears off, while aluminum is a soft metal that can gall or deform under even modest surface pressure.

For these reasons, we highly recommend cold rolled steel for linear motion. Despite being a commodity material, cold rolled bar maintains tight tolerances directly from the mill and is better suited to this application.