Wear and tear

It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage from wear and tear will not be covered.

[1] Wear and tear is a form of depreciation, which is assumed to occur even when an item is used competently and with care and proper maintenance.

This stress is impossible to prevent in the normal use of the tool for its designed task, and any attempt to avert it impedes its functionality.

A specialist may need to be consulted, such as an auto mechanic, a computer technician, a luthier, a gunsmith, or a plumber.

An automobile's engine may be repairable with a simple adjustment or replacement of a single and inexpensive broken part.