Abstract: The randomness of turning parameters will affect the diameter error. So， a reliability sensitivity analysis method for the diameter error of slender shaft is proposed. The shear zone model and geometric analysis method are used to establish the diameter error model. Kriging method is used to reconstruct the functional relationship between the machining error and the cutting parameters of slender shaft. The reliability sensitivity analysis is carried out by using the Monte Carlo method， and the influence degree of each parameter on the diameter error is evaluated. The results show that the system reliability increases with the increasing of cutting speed， tool rake angle and diameter， while it decreases with the increasing of cutting depth， cutting width， distance between tool holder and tool， and length diameter ratio of the slender shaft. The research results can provide theoretical basis for reducing the diameter error of slender shaft.

Key words: slender shaft machining; cutting force; diameter error; Kriging; reliability sensitivity