Hign-concerned Chemical : None Surface Roughness : Ra 0.05 Torque Capacity : 1.5x4x2MM Structure : Ball Model Number : 10Pcs 681X zz 1.5 4 2 mm fingerboard bearing smooth ABEC 9 Coatings : Chrome Steel Material : 52100 Chrome Steel Brand Name : FUSHI Origin : Mainland China Extra 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 Model: 681X ZZ Inner (d): 1.5 mm Outer (D): 4 mm Width (B): 2 mm Grade: ABEC-5 Material: 52100 Chrome Steel Seal: 2 Shield Qty: 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. 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 required for the effective function of bearing arrangements is correct lubrication. The lubricant separates the metallic bearing surfaces and thereby reduces friction, preserves the steel parts and acts as an additional barrier against the entry of contaminations or impurities into the bearings.