In order to investigate the possibility of punching process of brittle material by ball impact, effects of impact angle on cone crack formation in impact-loaded soda-lime glass were evaluated experimentally. Evaluated were also contact area between specimen and sealing, and the optimal condition for cone crack formation in glass plates by impact with small steel balls. It has been found that lateral and radial cracks gradually developed asymmetrically. However, the perfect cone cracks were found to develop almost symmetrically. As the impact angle increased, the growth rate of cone cracks decreased. Regardless of the impact angle, the PMMA sealing was more effective for perfect cone formation than Aluminum and Polyurethane sealing. Thus, the application for industrial technology for hole (or nozzle) punching process of the brittle materials is expected to be feasible, based upon proper selection of sealing materials.