Asme b89 3 7 defines standardized tolerance grades for surface plates.
Granite surface plate grades.
Plates that have ledges are used for clamping purposes only.
Types of surface plate.
The highest accuracy plates are called grade aa and they are often found in calibration laboratories.
Grade b plates are the lowest accuracy plates and they might be found on shop floors.
Grade s aa and a are the flattest with a flatness tolerances better than 0 00001 in for a grade aa plate.
Our granite surface plates are manufactured in three ledge types as well as standard sizes and grades.
Cast iron surface.
The overall flatness specifications of standridge granite products meet and surpass the requirements set forth by the federal.
Laboratory grade aa and a room inspection grade b and the fourth is workshop grade.
Surface plate grades and it s types basic terminology in surface measurement.
Granite surface plate have more rigidity for the same depth with the absence of corrosion.
Flatness is define by the distance between peak and depth point of surface.