The cooling process in metal molds is one of the important factors in the solidification process of molten metal. Molding defects, such as hot spot defects and warping, are usually present in cast products when cooling is not uniform. However, qualified and faster cooling positively affects product quality. Molding is one of the important processes both in terms of cycle time and product quality-, with permanent mold casting, high-quality liquid metal casting, and quality product. Selective Laser Melting (SLM) method was used to design metal mold cores with unique cooling channels to be compactly produced. The effects of the designed cooling channels, heat transfer, and solidification of the molten metal are studied in transient numerical terms. The temperature distributions at the 1st, 3rd, and 5th seconds after casting were obtained, and the solidification processes were investigated according to the standard cooling channels of the original cooling channels. According to the results obtained, it was observed that solidification would function better in the originally designed cooling channels. (C) 2019 Sharif University of Technology. All rights reserved.