Abstract Boring is one of the most common operations toenlarge or finish predrilled deep holes and is usually conducted in low spindle speed ranges. Due to low dynamic performances of conventional boring bar, boring operation is oftenhindered by drastic vibration. In this paper, a design and optimization method of a special boring cutter with constrainedlayer damping (CLD) bar is developed based on the CLDbeam theory and finite element method (FEM). The boringcutter designed is composed of four modules: cutting head,substrate layer, damping layer, and constrained layer, whichcan greatly improve the dynamic performances in boring process. Meanwhile, the effectiveness and capability of boringcutter with CLD bar for forced- and chatter-vibration suppression are presented based on experimental and numericalmethods. The results show that (1) the method for restrainingforced vibration is different from that for chatter suppression.The former can be greatly avoided by shifting the naturalfrequency of boring system, e.g., changing dynamic stiffness.The latter, due to its complexity in low spindle speed range, onthe other hand, cannot be entirely avoided and can only beeliminated by reducing the possibility of occurrence, e.g., increasing damping. (2) The boring cutter with CLD bardeveloped can change dynamic stiffness through constrainedlayer and improve damping performance through dampinglayer. So, it can avoid forced vibration and eliminate chatterto some extent. In the presented parameter domains, the capability of CLD bar for chatter suppression is improved fivetimes corresponding to that of conventional bar.Keywords Boring bar . Constrained layer damping .Parameter optimization . Chatter . Stability lobe diagram