永不生銹的螺絲釘 [－－－锈－－丝钉]

Jyutping
Pinyin yǒng bù shēng xiù de luó sī dīng

Definitions (CC-CEDICT)
  1. a "screw that never rusts" — sb who selflessly and wholeheartedly serves the Communist Party, like Lei Feng 雷鋒|雷锋[Lei2 Feng1], to whom the metaphor is attributed