Abstract In this paper, an automatic feature recognition system is proposed using object oriented approach. The part data is extracted from STEP file, which is the standard format for the most known CAD systems. The object oriented structure found quite useful for the generation of part geometric database. Both simple and interacting machining features considered in the study. Different algorithms developed for the extraction of feature faces along with their geometric properties and dimensions. The logical rules then formulated based on geometric reasoning to recognize the selected machining features. A case study presented to validate the proposed methodology.