Wear and tear is damage that naturally and inevitably occurs as a result of normal wear or aging. It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage due to wear and tear will not be covered.
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. For example, repeated impacts may cause stress to a hammer's head. In the normal use of a hammer for its designed task, this stress is impossible to prevent, and any attempt to eliminate it would make the hammer useless. At the same time, it is expected that the normal use of a hammer will not break it beyond repair until it has gone through a certain amount of use.
The phenomenon of wear and tear is a good demonstration of the Second Law of Thermodynamics in action - roughly speaking, objects will get messier and more worn down over time (they are said to have higher entropy), unless energy from the outside world is used to fix them.
A company which supports a warranty on a product with the possibility of wear and tear will usually limit the warranty to a period of time where its wear and tear will probably not be enough to impede the use of the product significantly. Other factors such as the willingness of a customer to replace a product through warranty will affect how long the company offers it.
Famous quotes containing the words Wear And Tear, wear and/or tear:
“You should hurry up ... and acquire the cigar habit. It’s one of the major happinesses. And so much more lasting than love, so much less costly in emotional wear and tear.”
—Aldous Huxley (1894–1963)
“Don’t order any black things. Rejoice in his memory; and be radiant: leave grief to the children. Wear violet and purple.... Be patient with the poor people who will snivel: they don’t know; and they think they will live for ever, which makes death a division instead of a bond.”
—George Bernard Shaw (1856–1950)
“[France is] a country where the money falls apart but you can’t tear the toilet paper.”
—Billy Wilder (b. 1906)