In this study. we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation. https://www.nacrack.com/hot-savings-HiBoost-Home-15K-Smart-Link-F20G-5S-IoT-limited-super/