The process of spin forming is frequently used for manufacturing the axial symmetric products. The spinning process is a transient dynamic contact problem, and is difficult to solve by the quasi-static theory. It is also found that the literature contains few Studies of spinning Simulation modeling. The present study deals with the dynamic FEM code, LS-DYNA, to simulate the conventional spinning processes based on the updated Lagrangian formulation. The applications of the mass scaling technique and contact algorithm between the roller and sheet are modeled. The modeling also considers the elasto-plastic material and Coulomb friction conditions. With the differences being variations in the rotation speed of the mandrel, the feed rate of the roller, and the material density. The predicted load-deformation relationships, the strain energy distributions, the full history of deformation states, and the influence and usage of the mass scaling factor are assessed. Some defects in the simulations are observed. and proper solution models are suggested. Besides, some results of the dieless spinning process using a cylindrical mandrel are compared with the conventional spinning process. The proposed models and techniques are helpful for the analysis of the spinning process, and will be a good approach for industrial metal forming simulation.