In the case where one or more secondary arrays of cutters are provided, each secondary array may also comprise {HEAD ~ cutters} spaced circumferentially apart around {TAIL ~ the central axis} of rotation of the drill bit and having cutting edges disposed at substantially the same radial distance from said axis 
In the case where one or more secondary arrays of cutters are provided , each secondary array may also comprise { HEAD ~ cutters } spaced circumferentially apart around { TAIL ~ the central axis } of rotation of the drill bit and having cutting edges disposed at substantially the same radial distance from said axis
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH