Mitsubishi Materials Corporation, or MMC, is a Japanese company. It is a manufacturer of cement products, copper and aluminum products, cemented carbide tools, and electronic materials. It is one of the core companies of Mitsubishi Group. The company is listed on the Tokyo Stock Exchange and the Osaka Securities Exchange, and is a constituent of the Nikkei 225 stock market index. In 2018 Mitsubishi Materials admitted that five of its subsidiaries, Mitsubishi Cable Industries Ltd., Mitsubishi Shindoh Co., Mitsubishi Aluminum Co., Tachibana Metal MFG Co. and Diamet Corp., had falsified quality data over the past three years on shipments including aluminium and automotive components. Mitsubishi Materials has started investigations at about 120 factories in its group. Wikipedia