The comparison of observed graphite particles with the structures shown in the charts give only purely descriptive information on the type, distribution, and size of the graphite in the sample being evaluated. It does not indicate except in a very broad way the origin of the graphite, or the suitability of the iron-carbon alloy for a particular service.

The Graphite Classification Test method covers the classification of graphite in cast irons in terms of type, distribution, and size. This test method is intended to be applicable for all iron-carbon alloys containing graphite particles, and may be applied to gray irons, malleable irons, and the ductile (nodular) irons

LMATS is NATA accredited to perform graphite classification in accordance with AS 5049 and ISO 945.

This test method is used to designate graphite microstructure in cast irons.