noun
replacement parts
Refers to spare or substitute parts used to replace worn or broken components in machinery, equipment, etc.
この機械の入替え部品はもう生産されていない。
Replacement parts for this machine are no longer produced.
交換部品 is a more common synonym for 'replacement parts', while 入替え部品 is less frequent but carries the same meaning.
Compound of 入替え (irekae, 'replacement') and 部品 (buhin, 'parts').