Zinc Alloy Housed Units (Silver Series) U000 series

Zinc Alloy Units U000 Series for flange mount bearing units
Insert bearings and wide inner ring bearings are used for mounting on shafts without the need for shoulders or adapters. The bearing is locked in place through setscrews or a locking collar. Housing Units (Silver Series)  U000 series have an inner ring that extends on both sides of the bearing and SB Style Insert Bearings extend on one side. 

Both designs however are intended to provide extra shaft support. Sometimes Bearing Housing Units (Silver Series)  U000 series are simply standard radial bearings that fit into a housing and these bearings may be purchased as stand-alone products to use as replacements. While standard radial ball bearings must be pressed into a machined shaft, using special installation tools, insert bearings can be slip fit directly onto the shaft.