In the current study, the DEFORM3D program was used to simulation of cold forming of spur gears using lead metal. Three different forms of billets were used to forming the spur gear and the choose of the size of billets was determined according to the size of suggested gear in this study. Analyzes were performed such as effect of stress, strain, average stress, total distance and speed during the formation process. Through the results of the values of the average stresses for the three billets, it was observed that the lowest value is obtained when using a solid billet. As indicated by the results of the study of the maximum stress occurs when the use of hollow billet with a diameter of 4 mm. In the study of effective stress, it was observed that there was a convergence in the stress values for all work pieces; these values in the age zone are greater than the center area. The results obtained from numerical modeling showed that the minimum effective strain occurs when using a hollow billet with a diameter of 4 mm and the highest value when using a solid billet. The velocity of the metal flow is proportional with the shape of the billet, it is noted that the value of the velocity in the case of hollow billets (4 mm and 6 mm) was close together and higher than the value of the metal flow velocity when using a solid billet. The speed of the metal flow is proportional with the amount of the billet cavity; in the case of the hard solid billet the speed is low. Peak load is affected during the formation of the spur gear with the shape of billet; it was observed that the peak load values of the 4 mm hollow billet were less than the peak load of the other two cases.