This document establishes terms, descriptions and characteristics and provides typical photos of specified surface imperfections which can be found on finished silicon nitride rolling elements.


Rolling elements refer to balls and rollers. Imperfections defined in this document correspond to patterns found on finished rolling elements before use.


Deviations for the geometric product specifications (GPS) are not addressed in this document.


This document does not give criteria for the acceptance limits of these imperfections. The identification of an imperfection is done between the different actors involved in the manufacturing, assembly or final use of the silicon nitride parts, depending on the technical specifications and the criticality of the application.