Series | 
                                                                        N/A 28900 | 
                                                                                Cone Part Number | 
                                                                        N/A 28980 | 
                                                                                Cup Part Number | 
                                                                        N/A 28921-B | 
                                                                                Design Unit | 
                                                                        N/A Inch | 
                                                                                Cage Material | 
                                                                        N/A Stamped Steel | 
                                                                                Related Assembly Number(s) | 
                                                                        N/A 28980-90060 | 
                                                                                d - Bore | 
                                                                        N/A 2.3613 in59.977 mm | 
                                                                                D - Cup Outer Diameter | 
                                                                        N/A 3.937 in100 mm | 
                                                                                D1 - Flange Outer Diameter | 
                                                                        N/A 4.0930 in103.962 mm | 
                                                                                B - Cone Width | 
                                                                        N/A 1.0000 in25.400 mm | 
                                                                                C - Cup Width | 
                                                                        N/A 0.7813 in19.845 mm | 
                                                                                C1 - Cup Flange Width | 
                                                                        N/A 0.1563 in3.970 mm | 
                                                                                T1 - Bearing Width to Flange | 
                                                                        N/A 0.3750 in9.525 mm | 
| R - Cone Backface "To Clear" Radius1 | N/A 0.14 in3.600 mm | 
| r - Cup Backface "To Clear" Radius2 | N/A 0.130 in3.30 mm | 
                                                                                da - Cone Frontface Backing Diameter | 
                                                                        N/A 2.64 in67 mm | 
                                                                                db - Cone Backface Backing Diameter | 
                                                                        N/A 2.87 in73 mm | 
                                                                                Da - Cup Frontface Backing Diameter | 
                                                                        N/A 3.90 in98.04 mm | 
                                                                                Ab - Cage-Cone Frontface Clearance | 
                                                                        N/A 0.09 in2.3 mm | 
                                                                                Aa - Cage-Cone Backface Clearance | 
                                                                        N/A 0.05 in1.3 mm | 
| a - Effective Center Location3 | N/A -0.1 in-2.5 mm |