This standard covers igneous rock (granite) plates for use in high accuracy locating, layout, and inspection work. It encompasses new certification, recertification in the field, and recertification after resurfacing. In general, the standard covers any size granite surface plate. Information for the sizes in common use is presented in tabular form. Concepts such as traceability and measurement uncertainty are also covered. This standard is a revision of Federal Specification GGG-P-463C: 1973.