Sub-micron fracture

A sub-micron fracture was a minuscule fracture that could be caused by neutron fatigue.

A sub-micron fracture in the metal casing of a dilithium chamber hatch replaced at Earth Station McKinley in 2367 was the cause for an explosion in the USS Enterprise (NCC-1701-D)'s dilithium chamber, and not sabotage by the Klingon spy J'Dan, as was originally suspected. The fractures were detected by means of microtomographic analysis.