To check the squareness of a workpiece to within .0002 inches, what tool would you use?

The tool that is most suitable for checking the squareness of a workpiece to within .0002 inches is a cylindrical square. This tool is specifically designed for ensuring that surfaces are at precise right angles to each other. A cylindrical square typically has highly accurate machining characteristics, enabling it to measure angular relationships with a high degree of precision.

In practice, a cylindrical square can be used to ascertain the squareness of edges or faces of a workpiece by aligning it against the workpiece and checking for any light gaps or inconsistencies that may indicate deviation from true squareness. This level of precision (to within .0002 inches) is critical in many machining and quality control processes, making the cylindrical square the ideal choice among the listed options.

Calipers and micrometers are useful for measuring dimensions and slight variations in thickness but are not intended for checking squareness specifically. A square ruler, while it can indicate squareness, does not provide the same level of precision and accuracy required for .0002 inches as a cylindrical square does.