Abstract The deformation mechanism of conventional spinning is studied in this paper through experiment and analysis. Three types of roller trace have been applied: straight line, concave curve and convex curve. As a result, all experiments have indicated that the deformation mode of conventional spinning of plates is quite different from that of the drawing process, but quite similar to that of shear spinning. Furthermore, when the original blank is a plate the deformation in the first pass has a decisive effect on the wall thickness distribution of the product of spinning.