Granite tables have been a popular choice for precision processing devices such as coordinate measuring machines, optical comparators, and surface plates. They are known for their exceptional stability and stiffness, making them an ideal choice for accurate measurements and precision machining. However, there are a few drawbacks to granite tables that need to be taken into consideration.
One of the first defects of granite tables is their susceptibility to temperature changes. Granite is a natural material that can expand or contract due to thermal variations. This can cause dimensional changes in the table, affecting its overall accuracy. To counter this, it is essential to maintain the temperature of the environment where the granite table is being used, as well as regular calibration.
Another issue with granite tables is that they are relatively brittle and can crack under heavy loads or impact. This can occur during transportation or under excessive weight. Hence, it is crucial to ensure proper handling and positioning of the granite table to prevent any damage. It is also advisable to carry out periodic inspections to detect any cracks or defects that may affect precision measurements.
Granite tables have a high level of porosity, which can lead to staining or chemical corrosion if they come into contact with certain substances. It is necessary to avoid exposing the granite table to acids, alkalis, or other chemical compounds that can corrode the surface or alter the properties of the material. Regular maintenance, including cleaning and sealing, can help protect the granite surface from any chemical damage.
Another defect of granite tables is that they may require regular maintenance and polishing to maintain their accuracy. Over time, the granite surface can become dull or scratched, affecting the measuring capabilities. Routine cleaning and polishing can help to restore the original smoothness and shine of the granite table.
In conclusion, granite tables are a suitable choice for precision processing devices, but they do have some defects that need to be taken into account. They require proper handling and maintenance to maintain their accuracy and prevent damage, as well as being vulnerable to thermal changes, chemical corrosion, and abrasions. However, with proper care and regular maintenance, granite tables can provide reliable and accurate measurements for many years.
