I dont have access to the latest grading standards for Chinas Hebei Black Granite. However, granite grading is typically done based on several factors such as color, pattern, texture, finish, porosity, density, strength, and other qualities. The grades can range from commercial to premium, with premium grades being the most durable and aesthetically pleasing. It is always recommended to verify the quality and grading of the granite with the supplier or manufacturer before making a purchase.