The basic principle in turning with groove-turn tools is the deflection of the cutting tool, which results in a frontal clearance angle αº between the insert and the workpiece. The clearance angle αº is a function of the side cutting forces and is not constant, as is the case with ISO inserts.

The deflection is influenced by the following factors:



When all of the above factors remain constant during turning, a high degree of accuracy with a tolerance up to ±0.01 mm can be achieved.
If the conditions are too light (such as in a super-finish operation), there may not be enough deflection and the clearance angle will be very small. This may result in chatter and vibration.