Hign-concerned Chemical : None is_customized : Yes Material : Bearing Steel Model Number : 624ZZ 4*13*5 MM bearing Brand Name : FUSHI Origin : Mainland China Certification : None Miniature Bearing Features Miniature Bearings can sustain some axial load in either direction as well as radial loads,And the two raceway cross-sections are simple circular arcs which can be very precisely finished so the bearings have low friction and very little noise or vibration.Several different cage designs are available with different characteristics and the choice depends upon the individual application. TECHNICAL SPECS (metric): Model: 624-ZZInner (d): 4 mmOuter (D): 13 mmWidth (B): 5 mmWeight (g): 3.0 gGrade: ABEC-5Material: 52100 Chrome SteelCover: 2 ShieldQty: 1 Lot = 10 Pcs This Bearing Structure Standard Type: A ball bearing is composed of an outer and inner ring, balls, seal and a retainer.Open type will no seal,Flanged type with flange side. This Bearing Cover Compared to the open type, the shielded and sealed bearing types provide better protection from contamination and grease leakage.They are selected based on the application type and environment.This is ZZ double shields. This Bearing Lubrication One of the most important elements requiredfor the effective function of bearing arrangements is correct lubrication.The lubricant separates the metallic bearingsurfaces and thereby reduces friction, preserves the steel parts and acts as an additional barrier against the entry of contaminations or impurities into the bearings.