O-Ring Size Charts O-Rings are commonly identified by the Inside Diameter (I.D.) and Cross Section (C/S) and are available in all standard AS568- sizes and European and Japanese Metric sizes. Select Cross Section Dimension to View O-Ring Sizing Chart: .070" (1/16) .103" (3/32) .139" (1/8) .210" (3/16) .275" (1/4) Boss Seals
