normal wear and tear; natural wear
Refers to the expected deterioration of an object over time through ordinary use, not due to accident or misuse. Common in legal, insurance, and maintenance contexts.
Under a rental contract, damage from normal wear and tear is not the tenant's responsibility.
Natural wear of this part is not covered by the warranty.
経年劣化 emphasizes deterioration due to aging over time, while 自然損耗 focuses on wear from normal use.
摩耗 specifically means abrasion or physical wearing away, often used for mechanical parts; 自然損耗 is broader and includes any natural deterioration.
Compound of 自然 (natural) and 損耗 (wear and loss). The exact historical derivation is uncertain, but the term is used in modern technical and legal contexts.