Which tool is best suited to check shaft or coupling alignment?

The straightedge and thickness gauge is the best tool for checking shaft or coupling alignment because it allows for a straightforward assessment of the alignment between two shafts or components. When using a straightedge, you can lay it across the faces of the couplings or shafts to identify any gaps or misalignments. This method is effective because it provides a visual and tactile way to detect variations in distance between the surfaces.

The thickness gauge can be used in conjunction with the straightedge to measure any gaps precisely. By inserting the thickness gauge into the spaces that may be present, a technician can determine how much adjustment is needed to achieve proper alignment. This combination of tools provides a reliable method for evaluating whether two components are correctly aligned, which is essential for efficient machinery operation and to minimize wear or damage.

While other tools like a transit could be useful in some alignment scenarios, they are generally more complicated and better suited for leveling or site work rather than precise mechanical alignment tasks. Calipers and micrometers are highly accurate for measuring dimensions but do not provide the alignment measurement functionality required in this context.