Not all knives are made from high-precision interchangeable parts. The pocketknife below was made by a small company that prides itself on using traditional methods of construction. Machine tools are used to stamp, cut, grind, and shape the parts, but those machine tools are guided by hand, not by computer.

The metal end caps at the top right are of slightly different lengths. I don't know whether they were trimmed to fit the handles, or whether the handles were trimmed to fit the end caps, but it's clear that somebody made these parts fit together.

This knife was constructed from a pile of parts that would have been interchangeable with parts used to make other knives in the same production run, but the parts of this knife were modified during the manufacturing process and are no longer interchangeable with the parts of other knives.