Formation of surface cracks formed by the rapid heating and cooling of the component.
Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards
A pattern of cracks on a metal surface caused by frictional heating followed by rapid quench cooling.
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards