Is aluminum better than steel for an underbody tool box?

Aluminum resists rust and weighs less, which matters on a truck frame exposed to road spray. Steel is stronger and cheaper but needs paint or coating to hold up.

What are the outside dimensions?

The box is listed at 36 in wide, 24 in deep and 24 in tall. Check your frame rail and ground clearance before ordering, since a 24 in depth hangs well below the bed.

Does it come with mounting hardware?

The listing does not include brackets or bolts. Plan on buying mounting hardware sized for your frame and drilling your own holes.

Will it keep water out?

It has a lid and latch, but budget aluminum boxes often need extra weatherstripping or sealant around the lid seam to stay dry in heavy rain.

Is $345.02 a good price?

It is the only new price found, $345.02 at The Home Depot as of November 8, 2026, so there is no recent range to judge it against. Compare it with similar 36 in aluminum underbody boxes before buying.