Bore size and outside diameter (OD) are important specifications to consider when selecting tapered roller bearings. The bore size is the bearing's smallest dimension. The outer diameter includes the bearing housing, but excludes the flange. Other important specifications for taper roller bearings include overall width, rated speed (oil), static axial load, static radial load, dynamic axial load and dynamic radial load. Static axial and static radial loads are, respectively, the maximum axial and radial loads that a bearing can withstand without permanent deformation. Dynamic axial load and dynamic radial loads are, respectively, the calculated axial and radial loads under which a group of identical bearings with stationary outer rings can endure for a rating life of 1 million revolutions of the inner ring.