Optimization of cutter profile for achieving maximum stiffness in five-axis milling of deep and narrow channel parts

•The concept of Cutter Profile Design Space (CPDS) for finding the stiffest cutter shape for five-axis machining of deep and narrow channel parts.•An efficient numerical method for calculating the CPDS with a reference five-axis tool path and a channel of smooth surfaces.•A PSO-based optimization algorithm for finding the best APT* standardized cutter with the maximum stiffness within any given CPDS.•Experimental examples of the proposed method that show its effectiveness in cutter shape optimization.