625ZZ Bearing 5x16x5mm ABEC 5 Double Shield Miniature Ball Bearings, 625 ZZ for Makefr RS CNC 32 Tutors (Pick of 10Pcs)

Structure of bearing 625:Inner & Outer Ring, cage, steel balls, grease, ZZ shield Pre-lubricated with grease:The main purpose of lubrication is to reduce friction and wear inside bearings that may cause premature failure. Nylon plastic retainers:Used for high speed rotation and low noise levels Made of chrome steel:The typical surface hardness for bearing components made from this material ranges from 60-64 on the Rockwell hardness C scale (Rc). Dimensions:Inner Bore=5mm; Outer Diameter=16mm; Width=5mm.