| 175 / | HD | BORING OR PENETRATING THE EARTH |
| 327 | DF | BIT OR BIT ELEMENT {21} |
| 331 | DF | .~ Rolling cutter bit or rolling cutter bit element {26} |
| 361 | ![]() | .~.~ Cross axle {3} |
| 362 | DF | .~.~.~> Vertically disaligned cross axle sections |
| 363 | DF | .~.~.~> Separable supports |
| 364 | DF | .~.~.~> Removable cross axle or bushing |