| 1935 |
Established at Riken (The Institute of Physical and Chemical Research) as a facility to manufacture and sell abrasive products based on Riken’s technologies for abrasive materials. |
| 1937 |
Completed Oji factory in Oji, Kita-Ku, Tokyo. Moved there from the Riken site. |
| 1938 |
Acquired a garnet mining right in Kawaba ,Gunma Prefecture and built the Numata Factory. |
| 1953 |
Completed the development of a system for static electricity coating (Patented: Received a development grant from the Agency of Industrial Science and Technology organized under the Ministry of International Trade and Industry). |
| 1956 |
Completed the development of a high-precision production line for coated abrasives (funded by the Ministry of International Trade and Industry). |
| 1958 |
Completed a full production line for wide belts at the Oji factory. |
| 1960 |
Listed on the second section of the Tokyo Stock Exchange. |
| 1965 |
Built the Konosu factory in Konosu-City, Saitama Prefecture. |
| 1970 |
Concluded a technical agreement for the manufacture of coated abrasives with Norton U.S.A. and established Riken Norton Co., Ltd. |
| 1976 |
Succeeded in the first domestic production of Zirconia abrasive products, and launched their production and sale. |
| 1978 |
Acquired a 100% share of Riken Norton Co. and renamed the company Riken Corundum Co., Ltd. |
| 1981 |
Merged with Riken Co., Ltd. |
| 1982 |
Built the Riken Kamiya Building on a vacant let next to the Oji factory. (Presently renting the building to Daiei, one of the leading superstores in Japan.) |
| 1990 |
Discontinued the technical agreement with Norton. |
| 1996 |
Built the Niiharu factory in Niiharu, Tone, Gunma Prefecture. |
| 2002 |
Established Riken MT Coated Abrasives as a joint venture in China. |
