​     Due to the fact that granite is a very hard material and is not greatly affected by temperature fluctuations, it is ideal to use as a reference surface for all your calibration. However, as with any other material, with continual use, the surface plate will wear over time. Some causes of this are airborne abrasive dust, repeated sliding of gages, or simple daily wear will create wear spots that are invisible to the naked eye. These spots affect the flatness of the plates, therefore, compromising the accuracy of the measurements that you make on it giving you less confidence in the readings that you are getting. Granite surface plate calibration will give you the confidence you need by ensuring accurate measurements and quality standards. 

    McCune's Instruments offers ISO 17025 accredited surface plate calibration. Our accredited granite surface plate calibration covers grades AA, A and B. We also offer granite surface plate resurfacing, if needed, with a relap to bring surface plate back into specification.