What tool is often used to check for frame squareness?

A frame alignment machine is specifically designed to check and ensure the squareness of a vehicle's frame. This tool uses precision measurement technology to assess the straightness and alignment of the frame, which is crucial for proper structural integrity and to ensure that all components will fit together correctly. The machine often incorporates multiple sensors and lasers to provide a detailed readout of any misalignments, making it an essential tool in structural analysis and repair.

In contrast, while a laser measuring tool might be useful in various measurements, it does not provide the specialized functions of a frame alignment machine tailored for assessing frame squareness. A torque wrench is designed for tightening fasteners to a specific tension and does not measure alignment. Likewise, a caliper gauge is used for measuring the dimensions of parts but lacks the capacity to assess the overall squareness and alignment of the frame itself. Thus, the frame alignment machine is the most appropriate choice for this application.