In the Tractor
There are a number of applications in the tractor that utilize extrusions, with specifics varying by manufacturer. The cabs of some brands are steel-intensive, others are aluminum-intensive. Trucking operates in a brutal environment (including corrosive road salts) so durability is critical.
With aesthetics and branding increasingly important - and because aluminum forms a natural oxide to protect against corrosion - extrusions are often visible and free of paint.
One OEM has 45 extruded part numbers within the tractor, and they are supporting components from front to rear including the fuel tanks, fenders, mud flaps, engine component mounts, radiator supports and the aerodynamic shield brackets, to name a few.
Moving Towards Electrification
As with autos, truck builders are moving towards electrification in order to reduce emissions and improve fuel economy. With the onset of electrification comes the need to protect the battery pack from side impact, and the the image at right shows one such extrusion that provides structural support and protection.
Source: Taber Extrusions
Within that electric truck is a battery pack. When possible, battery packs are positioned between the frame rails for support, and crash protection. The automotive market has determined that aluminum extrusions are a great material for EV battery boxes, and the story is the same for the Proterra battery packs in commercial trucks and buses.
Source: Proterra.com