Counter bore tools offer the advantages of throwaway index able carbide inserts. Counter bore tools are offered in any size with single, double or triple cutting edges based on the size. Freely available standard carbide inserts are used. Pilots are detachable types, which permits the use of different dia of pilots for the same dia of counter bore. This feature also enables an easy replacement of damaged worn-out pilots. To facilitate easy chip flow, well-designed gashes and relief are provided on the tool shank.