1.1 This guide covers the description of carbide structures in annealed high carbon bearing steels. 1.2 Included is a guide for rating steel specimens by a graded series of photomicrographs showing the incidence of certai This guide covers the definition and rating of the microstructure of carbide structures in annealed high carbon bearing steels. Requirements for the optical metallograph apparatus and specimen preparation including polishing and etching are detailed. T