As rock condition is a key factor to cutters selection. The following is a table of rock condition.
|
Rock |
Compressive Strength Sd（MPa） | Tensile trength Sz (MPa) |
Characteristics |
||||
| min. | average | max. | min. | average | max. | ||
| Sandstone | 25 | 170 | 320 | 5.1 | 17.3 | 30.7 | High abrasiveness, massive |
| Siltstone | 30 | 95 | 180 | 4.1 | 8.5 | 19.0 | Low abrasiveness, inhomogenous |
| Basalt | 50 | 145 | 280 | 7.3 | 14.0 | 23.3 | Soft, fissures, can be split |
| Slate/Schist | 55 | 110 | 250 | 9.3 | 13.6 | 31.1 | Fissures and cracks present |
| Gneiss | 55 | 140 | 330 | 7.7 | 17.2 | 30.6 | Cracks, fissures and crevices present |
| Marble | 60 | 120 | 175 | 6.0 | 11.0 | 18.5 | Non abrasive, cracks |
| Limestone | 75 | 130 | 270 | 7.2 | 11.9 | 23.2 | Non abrasive, brittle |
| Granite | 85 | 170 | 285 | 7.8 | 13.8 | 22.5 | Hard and massive, few cracks and fissures |
| Dolomite | 85 | 195 | 315 | 12.5 | 16.8 | 21.6 | Very abrasive but massive, high strength |
| Amphibolite | 110 | 195 | 280 | 17.2 | 18.6 | 22.0 | Tough rock, not desirable |
| Diorite | 120 | 135 | 150 | 13.8 | 14.5 | 15.0 | Hard and massive, few cracks and fissures |
| Andesite | 150 | 190 | 240 | 12.0 | 17.9 | 23.8 | High strength, fine grained |
| Quartz | 240 | 280 | 340 | 15.3 | 19.0 | 24.3 | Very abrasive, massive, homogenous |