Abstract: A two part drill bit assembly and to the two drill bits that form the assembly. The drill bits are releasably engageable, to form the assembly, via compatible spiral grooved surfaces on each bit with one of the drill bits being re-useable and the other intended for single use or being made otherwise disposable.

Abstract: A drilling assembly for simultaneously drilling a hole and inserting a friction bolt, the drilling assembly comprising a drill string, a drill bit and a friction bolt, wherein: (i) the drill string defines a leading end adapted to releasably operatively connect to the drill bit and a trailing end adapted to operatively engage with a means for imparting energy on said drill string; (ii) the drill bit is mounted on the leading end of said drill string; (iii) the friction bolt at least partially surrounds said drill string; and wherein (iv) the drilling assembly further comprises an elongate spacer that defines a leading end and a trailing end and is located between said friction bolt and said means for imparting energy on said drill string.

Abstract: A drill bit for a drill assembly including a friction bolt defining a longitudinal axial passage, the drill bit being adapted to be releasibly attached to the friction bolt and comprising: (i) a leading end including a cutting part; (ii) a following end; and (iii) an outer surface defining a friction bolt engaging means adapted to releasibly engage with the leading end of the friction bolt.

Abstract: A cartridge inserter adapted for use in insertion of a cartridge into a rock bolt hole drilled in rock in an underground mine, said inserter comprising a tube portion (11) having an opening (12) at one end which opens into the interior of the tube portion (11), the interior region of the tube portion being adapted to receive a cartridge, the tube portion being adapted to be insertable within a rock bolt hole. Also provided is a method for installing a cartridge by the use of the inserter (11) and a cap being receivable within the opening (12) and adapted to support the cartridge within the rock bolt hole.