ISO 13778:2017 specifies the selective assembly of bearings (in accordance with ISO 3548-1).
The bearing diametral clearance is determined by the housing diameter, journal diameter and the wall thickness of the two half bearings. Typically, these components will have a total tolerance "stack up" of 50 µm to 60 µm. Current engine development and in particular, the desire for improved engine refinement, has provided a need to decrease the clearance range due to the tolerance "stack up". This document suggests various schemes of selective assembly to achieve such ranges.