Black granite material.
Squareness made according to DIN875.
| Specification (mm) | Squareness Between Measuring Surface and Datum Surface | Flatness and Straightness of Measuring Surface | Flatness and Straightness of Datum Surface |
| Accuracy Grade (μm) |
| 00 | 0 | 00 | 0 | 00 | 0 |
| 100×63 | 2 | 4 | 1 | 1 | 1 | 1 |
| 160×100 | 2 | 4 | 1 | 2 | 1 | 1 |
| 250×160 | 2.5 | 5 | 1 | 2 | 1 | 2 |
| 400×250 | 3.5 | 7 | 1 | 2.5 | 1 | 2 |
| 630×400 | 4.5 | 9 | 1.5 | 3 | 1 | 2.5 |
| 800×500 | 5 | 10 | 2 | 4 | 1.2 | 3 |
| 1000×630 | 6 | 12 | 2.5 | 5 | 1.5 | 3 |
| Specification (mm) | Squareness Between Measuring Surface and Datum Surface | Flatness and Straightness of Measuring Surface | Flatness and Straightness of Datum Surface |
| Accuracy Grade (μm) |
| 00 | 0 | 00 | 0 | 00 | 0 |
| 100×63 | 2 | 4 | 1 | 1 | 1 | 1 |
| 160×100 | 2 | 4 | 1 | 2 | 1 | 1 |
| 250×160 | 2.5 | 5 | 1 | 2 | 1 | 2 |
| 400×250 | 3.5 | 7 | 1 | 2.5 | 1 | 2 |
| 630×400 | 4.5 | 9 | 1.5 | 3 | 1 | 2.5 |
| 800×500 | 5 | 10 | 2 | 4 | 1.2 | 3 |
| 1000×630 | 6 | 12 | 2.5 | 5 | 1.5 | 3 |
