Specifying fastening hardware in load-bearing environments carries incredibly high stakes. Mechanical failure is simply not an option. You rely on these components to hold massive structures and critical machinery together under immense stress.
Specify the wrong dimensions for a push button locking pin, and the assembly either fails to lock entirely or suffers from excessive axial play. This loose tolerance accelerates mechanical wear. The most common point of failure in procurement involves confusing "overall length" and "grip length."
Exacting engineering environments leave absolutely no room for guesswork. A fraction of a millimeter often determines whether an assembly holds under immense pressure or fails catastrophically.