Dust cover is a circular hood, usually composed of sheet metal stamping, fixed on the bearing of a ring or a washer, and extends toward another ring or washer and obscure bearing internal space, but not contact with another ring or washer.

Dust cover type can be divided into retaining ring type steel bearing dust cover and stamping steel plate bearing dust cover.

Retaining ring type steel bearing dust cover: miniature bearings, metal stamping processing steel plate with a spring ring is fixed on the outer ring of the structure.
Stamping steel plate bearing dust cover:reduce grease exudation, the metal steel plate by stamping processing and the structure of the reinforcement on the outer ring.