To improve the drilling hole straightness guide tubes or pilot tubes are used as the first rod of the drill string. As the guide tube has a diameter as close as possible to the one of the bit, the drill string ends up becoming very stiff. This guiding action of the tube offers nearly the same straightness that offered by DTH drilling.
Please click on the link below to view the available guide tubes with Rocksmith. Copy and paste the selected line item in the form and click send for Rocksmith to offer you a price quote.