Starrett Granite Surface Plates

Starrett’s granite surface plates meet or exceed Federal Specification GGG-P-463c requirements and are provided with NIST Traceable calibration certificates. A2LA Accredited calibrations are available upon request. Long form, graphed reports of the inspection surface of the granite plate are also available upon request for an additional charge.

The plates are available in Grades AA (Laboratory), A (Inspection) or B (Shop or Toolroom) and are offered in Crystal Pink or Superior Black Granite.

They are produced to support 50-lbs per square foot loading, loaded in the center of the plate. This means that the designated load may be placed in the center of the plate without deflecting the overall accuracy more than 50 percent.

Granite Surface Plate Options


  • Crystal Pink Granite Surface Plates – Accurate for use in metrology labs and durable enough for the shop floor. The pink color comes from a very high crystalline quartz content. Even distribution of large quartz crystals provides a smooth finish. Plates meet or exceed 50 lb per square foot (24 kg per 1,000 sq cm) load bearing specifications and U.S. Federal Specification GGG-P-463c for flatness. These plates offer great surface hardness and wear resistance – the highest percentage of quartz crystals of any granite plate – and have smooth, jewel-like quartz bearing points to protect accuracy and finish of both the surface and the tools used on the plate. It provides combined quality and economy and is comparable to black granite plates while outwearing them as much as 5 to 1.
  • Superior Black Granite Surface Plates – These plates minimize thermal expansion and have low water absorption rates to minimize rusting of precision gages. They have very little glare resulting in reduced eye strain.