| IADC | Recommendation | Applicable Formation |
| WOB | RPM |
| 117 | 0.35~0.8 | 240~80 | Very soft formations with low compressive strength and high drillability, such as clay, mudstone, chalk, etc. |
| 127 | 0.35~0.9 | 240~70 | Soft formations with low compressive strength and high drillability, such as mudstone, gypsum, salt, soft shale, soft limestone, etc. |
| 437 447 | 0.35~0.9 | 240~70 | Very soft formations with low compressive strength and high drillability, such as clay, mudstone, chalk, gypsum, salt, soft shale, soft limestone, etc. |
| 517 527 | 0.35~1.0 | 220~60 | Soft formations with low compressive strength and high drillability, such as mudstone, gypsum, salt, soft shale, soft limestone, etc. |
| 537 547 | 0.45~1.0 | 220~50 | Soft to medium formations with low compressive strength, such as medium soft shale, medium soft limestone, medium soft sandstone, medium formation with harder and abrasive interbed, etc. |
| 617 627 | 0.45~1.1 | 200~50 | Medium hard formations with high compressive strength, such as hard shale, limestone, sandstone, dolomite, etc. |
| 637 | 0.5~1.1 | 180~40 | Hard formations with high compressive strength, such as sandstone, limestone, dolomite, hard gypsum, marble, etc. |
