The term “granite plate precision grade 000”
Is there a Grade 000 for granite surface plates? Core ConclusionIn the current national standard GB/T 20428-2021 “Flatness of Rock Plates”, there is no Grade 000; it only defines: Grades 00, 0, 1, and 2.The old national standard GB 4987-85 did have a Grade 000, which has now been abolished, but the industry, manufacturers, and…