Grade s aa and a are the flattest with a flatness tolerances better than 0 00001 in for a grade aa plate.
Granite surface plate grades.
Grade b plates are the lowest accuracy plates and they might be found on shop floors.
The highest accuracy plates are called grade aa and they are often found in calibration laboratories.
Plates that have ledges are used for clamping purposes only.
Types of surface plate.
Asme b89 3 7 defines standardized tolerance grades for surface plates.
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.
The overall flatness specifications of standridge granite products meet and surpass the requirements set forth by the federal.
Our granite surface plates are manufactured in three ledge types as well as standard sizes and grades.
Workshop grades being the least flat and as the name suggests they are intended for use in tool rooms.
The middle grade plates grade a are often used in inspection areas.
Granite surface plate have more rigidity for the same depth with the absence of corrosion.