The Xs F can be used with any size of casing. The life of this system is much improved because of its geometry which has two (2) internal shoulders (donut). One transfers impact to the drive shoe, giving the necessary force to drive down casing. The second transfers energy directly to the crown bit for drilling.
The driver bit is the device that transfers impact and rotation to the crown bit for drilling. The driver bit locks into two flats on the casing crown and they act together as a standard drill bit, both the driver bit and the crown have tungsten carbide buttons. The Driver bit drills a pilot hole of 3″ below the crown to guide the direction of the casing in rough drilling.
The crown bit is a single unit with Tungsten carbide, held on the driver only by the locking surface.