How long is the auger type 360?
It extends in the first order, the next second, and then the third, the last, the fourth, and the fifth. During drilling, it is stretched by gravity and bit by bit with the drilling depth. Rotary drilling rig in the multi-functional areas to improve, and it is not necessary to complex conversion can be converted to another device, it is worth studying.
The drill rod of the rotary drilling machine is now extended from the lower part of the hoist, the steel wire extends out, and the hoisting rope is retracted. But some rotary drills can be extended either by a crane or by gravity.
The thickness of each drill string is controlled sequentially. Extend from coarse to fine. Retract from thin to thick.
