Facing

Only positive inserts with a built-in flank clearance of 7° or more are suitable for internal facing. Use the shortest possible bar with the biggest possible diameter.

An entering angle that is as large as possible is vital. For a normal cutting head, this means radial feed outwards from the smallest diameter, rather than inwards from the biggest diameter.

When the bottom is facing towards the centre of the work piece, deflection of the bar will most likely leave a pip, which in worst case can break your inserts if the bar travels past the centre. The challenge is to make the cut light enough to keep deflection within acceptable limits, and still remove material.

In backfacing it is very easy to overload the bar as the tangential deflection of the bar will increase the depth of the cut in the axial direction, and increase the cutting forces, which again will increases deflection.

Silent Tools® is a definition of tool holder made to reduce vibrations due to a damper inside the tool body and is a trade mark of Teeness ASA. Damped boring bars are designed for high productivity, close tolerances and overhang beyond 4 x the bar diameter.