Miniature Ball Bearing Bearing Industry Number 628 Bore Diameter 8 mm Closure Double Shielded For Environment Oily/Greasy Outer Ring Width 8 mm Outside Diameter 24 mm Ring Material Alloy Steel System of Measurement Metric ABEC Rating 1 Ball Material Alloy Steel Ball Material Grade AISI 52100 Bore Diameter Tolerance +0/-0.008 mm Cage Type Shielded Dynamic Radial Load Capacity 750 lbf Includes Retaining Ring No Lubricant Material Polyrex EM