Granite Precision Machined Component Accuracy (Official Standards Industry Real-World Testing)
The machining accuracy of granite precision components can reach up to Grade 000, with flatness ≤0.5μm/m and dimensional accuracy ±1μm, classified as ultra-precision grade.
I. Accuracy Grades (National Standards / Industry General)
Grade 000 (Highest)
Flatness: ≤0.5μm/m
Applications: CMMs, roundness testers, semiconductor optical bases, ultra-precision inspection platforms
Grade 00 (High-end Mainstream)
Flatness: ≤1μm/m
Applications: Precision inspection platforms, vision instrument bases, machine tool beds
Grade 0 (Mid-range)
Flatness: ≤2μm/m
Applications: General inspection plates, tooling datum tables
Grade 1 and below (Standard)
Flatness: ≥3μm/m
Applications: General layout, assembly datum
II. Key Precision Indicators (Industry Leading Level)
Flatness: Up to 0.3–0.5 μm/meter
Straightness: Up to 0.5 μm/meter
Parallelism: Up to ±1 μm/meter
Perpendicularity: Up to ±1 μm/meter
Dimensional Accuracy: ±1 μm
Surface Roughness: Ra ≤ 0.05 μm (Mirror finish)
III. Which Granites Can Achieve the Highest Precision?
Jinan Green: Stable Grade 000 (Top-tier)
Indian Stone (Indian Black Gabbro): Stable at Grade 00 to 000
Zhangqiu Stone / Northeast Material: Generally Grade 0 to 00; difficult to stabilize at Grade 000
