Start form the description on section contour of componen t parts of non-circular section with equal width,the designing method of sectional contour of component parts with section of equal width was presented,the new mo del of combined turning and milling machining for arbitrary non-circular parts w ith section of equal width was proposed.

Using geometric simulation and based on experimental data, the existing spread mathematical models are compared and a regression spread model is established in this paper.

By choosing the structure of spread model and the mathematical analysis of the shape factor of rollpass, a designing idea to obtain geometric shape according to strain factor has been built.