Dry machining is a machining process without coolant and it has more popular as a finishing process. The purpose of this paper was to obtain a comprehensive understanding of the relationship between input data i.e. speed, feed and depth of cut and output data i.e. residual stress during dry machining with CBN cutting tool on hardened steel [En31]. In present study L27 orthogonal array test plan was used. Neuro fuzzy model [CANFIS] is developed and sensitivity analysis is carried out to measure the relative importance of the input parameters of the model and how the model output parameter varies in response to variation of an input.