For example, we may say that foods are sterile even when they really aren't. They can be commercially sterile, which pretty much means "sterile enough". There are still bacteria there, just a very minimal amount.

Theoretically it might be possible to measure the hardness of a cuendillar bar and see it go up as you apply pressure to the bar, or something. But since it's already the hardest thing in existence, what's the point? It's indestructible, for a given value of indestructible.