BORING TOOL WITH SUPPORT ELEMENT

The invention relates to a rotating cutting tool, in particular a boring tool for use in machine tools. The cutting tool comprises at least one cutting insert, designed as an indexable insert, that has an active main blade located near a corner of the insert, the outer end of said blade defining a circular flight path radius (R) as the blade rotates, said blade penetrating into a work piece at a pre-determined cutting depth (t) near a pre-formed round hole. Also provided is a secondary blade that is disposed opposite to an advancing direction and that aligns with the outermost end of the main blade, the entire length of said blade having a smaller radius than the circular flight path radius (R) of the main blade, wherein a secondary blade free surface aligns with the secondary blade opposite to the direction of rotation. A unique characteristic of the invention is that the secondary blade free surface comprises a support part disposed at a distance from the secondary blade, the peripheral radius of said part being larger than the circular flight path radius R of the active main blade by an overshoot amount (Y).