1927 Meguro Laboratory (Tokyo) of Mitsui Mining Co., Ltd. started manufacturing grinding wheels.
1933 Regular operation started.
1952 Company name changed to Mitsui Mining and Smelting Co., Ltd. The plant became Meguro Grinding Wheel Plant of the company.
1963 Technical tie-up for gear honing grinding wheels agreed with National Broach of USA.
1968 Due to lack of space at Meguro Plant, relocation to Musashi Industrial Park in Iruma-shi, Saitama started.
1973 Removal of plant completed, creating the newest & most powerful plant in the industry.
1974 Spun off from Mitsui Mining and Smelting Co., Ltd. to become an independent company. Mitsui Grinding Wheel Co., Ltd. established.
1976 CBN Wheels and Diamond Wheels began to be marketed.
1995 Mitsui Grinding Technology (Thailand) Co., Ltd. established.
1999 Expansion of production capacity for 108 ton/month and also increased the capital investment to 218.75 million baht due to the rapidly higher demand from all customers around the world.
2001 ISO 9001 certification acquired.
2004 Expansion of production capacity for 283 ton/month. Set up the Research and Development (R&D) section to develop products and process technology in order to raise up production qualities.
2010 ISO 9001:2008 system control certification acquired.
2016 Expansion of production capacity for more than 300 ton/month by expanding firing