Granite (high-quality natural granite such as Jinan Green) guide rails are the core reference components of precision machine tools, CMMs, and inspection equipment. Ultra-high precision is their most core selling point.
- Extremely low coefficient of linear expansion and excellent temperature stability
Compared to cast iron and steel, granite has a much smaller thermal expansion coefficient. When the ambient temperature changes slightly, the deformation of the guide rail itself is minimal. In a constant-temperature workshop, it can stably maintain micron-level precision without rapidly expanding or causing dimensional drift like metal parts, making it suitable for high-precision measurement and cutting scenarios. - Natural internal stress is almost completely released, ensuring long-term dimensional stability
High-quality granite has undergone geological aging over hundreds of millions of years, resulting in extremely low residual internal stress. After machining, it will not slowly deform over time like castings. The straightness and flatness of the guide rail can be maintained for a long time, with minimal precision degradation even after years of equipment use, ensuring long-term repeatability. - Uniform material, capable of being ground to extremely high geometric tolerances
The stone has dense and uniform grains, which can achieve nanometer-level surface roughness through fine grinding and scraping. Flatness, straightness, and parallelism can easily reach Grade 00 and Grade 000 reference accuracy. The friction of the kinematic pair is uniform, the motion is smooth, and crawling is reduced, ensuring accurate output for micro-feed and precision inspection. - High rigidity and good damping, suppressing precision loss caused by vibration
The damping of granite is much higher than that of steel/cast iron, so vibrations generated by cutting or motion will decay rapidly. Small vibrations will not cause the guide rail surface to shake, avoiding contour errors caused by vibration. In high-speed precision motion and micro-measurement scenarios, it ensures that precision is not compromised by vibration. - Wear-resistant, corrosion-resistant, and strong precision retention
The entire material consists of mineral crystals, so it does not rust and is not corroded by cutting fluids; it has high hardness and good wear resistance. The long-term sliding wear on the guide rail working surface is very small, making it difficult to lose the original reference accuracy due to surface wear, thereby reducing the cost of later precision maintenance.
