Omni mb 100 and 200 microboring heads , from accurate engineering industries are readily adaptable on milling and boring machines with h 30, iso 30, iso 40, iso 50 spindle bore taper. All omni boring heads have clearly graduated, hardened lead-screw. A distinctive characteristic of these microboring heads is their thread back which can be fitted with interchangeable shanks. Since space is a key factor, the overall length of boring heads is held to a minimum. This feature contributes to greater tool rigidity which in turn assures good finish and accurate bores.