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 |