Why Choose Granite for CMM Machine (coordinate measuring machine)?

The use of granite in 3D coordinate metrology has already proven itself for many years. No other material fits with its´ natural properties as well as granite to the requirements of metrology. The requirements of measuring systems regarding temperature stability and durability are high. They have to be used in a production-related environment and be robust. Long-term down times caused by maintenance and repair would significantly impair production. For that reason, CMM Machine companies use granite for all important components of measuring machines.

For many years now, manufacturers of coordinate measuring machines trust in the quality of granite. It is the ideal material for all components of industrial metrology which demand high precision. The following properties demonstrate the advantages of granite:

• High long-term stability – Thanks to the development process which lasts many thousand years, granite is free of internal material tensions and thus extremely durable.

• High temperature stability – Granite has a low thermal expansion coefficient. This describes the thermal expansion at the temperature changing and is only half that of steel and only a quarter of aluminium.

• Good damping properties – Granite has optimal damping properties and thus can keep vibrations to a minimum.

• Wear-free – Granite can be prepared that a nearly level, pore-free surface arises. This is the perfect base for air bearing guides and a technology which guarantees the wear-free operation of the measuring system.

Based on the above, the base plate, rails, beams and sleeve of the coordinate measuring machines are also made of granite. Because they are made of the same material a homogeneous thermal behaviour is provided.