CORE BITS- Selection chart
Rock Characteristics |
|
Extremely Hard Non-Abrasive Very Fine Grained Competent
|
12-15
10-12 |
| Very Hard Non-abrasive Fine Grained Competent |
8-10
7-9 |
| Hard Moderately Abrasive Fine To Medium Grained Competent to Fractured |
7-9
6-8 |
| Medium Hard Moderately Abrasive Medium to Coarse Grained Competent to Fractured |
6-8
6 |
| Medium Soft Abrasive Medium to Coarse Grained Competent to Fractured |
2 |
| Very Abrasive Coarse Grained Highly Fractured Abrasive |
1 |
