Starting borers |
Starting borer is a pipe with prefabricated flange welded to outside surface. The flange is 10-20 mm width. It is covered with coat of cast tungsten carbide of not less 5 mm width. The bottom of supporting pipe is connected to starting borer case. Also blades, armoured with buttom inserts, are welded to case. Blades and revolving picks are located with the tilting about the axis of borer. Blades’ cases die to flange. Such construction guarantees effective removal of distruction products and higher speed of drilling. All changeable elements of a borer are armoured with hard-alloyed bits of alloy VK8. Special features:
Spares |