At UNPARALLELED® Group, our granite precision platforms are engineered for ultra-precision measurement and assembly applications. One of the most important factors in platform performance is material hardness, which directly affects durability, wear resistance, and long-term reliability.
Granite Hardness
UNPARALLELED® uses high-density black granite (~3100 kg/m³) for its precision platforms. Granite is naturally very hard, typically achieving a Mohs hardness of 6–7, far exceeding common industrial materials. This hardness ensures excellent resistance to scratches, dents, and surface deformation, even under heavy use in industrial environments.
Comparison with Cast Iron
Cast iron platforms are widely used in many workshops and laboratories due to their rigidity and cost-effectiveness. However, their hardness generally ranges from 150–200 HB (Brinell hardness), which is lower than granite's natural hardness. While cast iron provides structural stability, it is more prone to wear, scratches, and surface damage over time, especially in high-precision applications.
Granite platforms offer several advantages over cast iron:
Superior Wear Resistance: The high hardness of granite ensures a long-lasting, flat, and stable surface.
Thermal Stability: Granite has a lower coefficient of thermal expansion than cast iron, reducing measurement errors caused by temperature fluctuations.
Chemical Resistance: Granite is resistant to most industrial chemicals, while cast iron can corrode or oxidize over time.
Vibration Damping: Granite's dense crystalline structure naturally absorbs vibration, enhancing precision measurement.
Why Granite is Preferred for Ultra-Precision Applications
Due to its high hardness and excellent wear resistance, granite has become the material of choice for CMM bases, surface plates, and high-precision assembly platforms. At UNPARALLELED®, our granite precision platforms maintain nanometer-level flatness and superior surface durability, providing reliable measurement and calibration for decades.
Conclusion
When comparing granite and cast iron, granite clearly outperforms in hardness, wear resistance, thermal stability, and vibration damping. This is why UNPARALLELED® exclusively uses high-density black granite in its precision platforms, ensuring long-term accuracy and reliability for ultra-precision industries worldwide.