Abstract: An accurate apparatus for cutting, and exactly centering, an annular crown of V cross section, on the end edge of the hollow cylindrical drill tube of a diamond core drill bit is achieved by a bit veeing cutter head having a pair of horizontal spaced apart flat planar plates forming a housing for a pair of arms of rectangular cross section, each pivoted to the other at one end and each having a roller cutter at the other end. The flat planar outer faces of the arms slidably contact the flat planar inner faces of the plates, to prevent cutter fluctuation, loose pivoting or off center V shaping of the annular crown.