Hign-concerned Chemical : None Surface Roughness : Ra 0.05 Torque Capacity : 3X6X2.5mm Structure : ECCENTRIC Model Number : MR 63 ZZ Bearing For Shimano Mill, NOT FOR ISB EZO NMB Coatings : NICKEL Material : STEEL Brand Name : FUSHI Origin : Mainland China Certification : RoHS,None Miniature Bearing Types & Features Miniature and instrument ball bearings can be divided into two basic types, deep groove and angular contact. The first (deep groove) can also be classified as "Open", "Shielded", or "Sealed" depending on the existence and type of seal or shield. Deep groove ball bearings have two inherent advantages; they 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. Pic1: Showing contacts between the rolling elements with inner and outer raceways. Pic2: Through stress life fatigue analysis, it shows that the high precision bearing has longer fatigue life and higher safety factor. TECHNICAL SPECS Model: MR63ZZ Inner (d): 3 mm Outer (D): 6 mm Width (B): 2.5 mm Grade: ABEC-5 Material: 52100 Chrome Steel Seal: Shield Qty: 1 Lot = 10 PCS