This work is concerned with the chatter suppression by inserting viscoelastic materials between tool and toolpost.
The tool has enough length in order that the tool is the main cause of the chatter and then the viscoelastic materials insert between tool and toolpost. The stiffness and damping change due to the insert material is found by the impact test for the tool and finite element analysis for the toolpost, the cutting error due to the stiffness decreasement of the toolpost in stable cutting condition is estimated.