| 1926 || Dr. Keikichi Ebihara of the Okochi Research Laboratory of the Institute of Physical and Chemical Research invented a manufacturing method for piston rings that insured uniform pressure on the inner wall of the cylinders. Patents were obtained from various countries. |
| 1927 || In order to commercialize the inventions of the Institute of Physical and Chemical Research, Rikagaku Kogyo was established (predecessor of the Riken Corporation) with a capitalization of ¥3,000,000. The company was the first to begin the mass production of piston rings in Japan. |
| 1932 || The Kashiwazaki plant was constructed in Niigata Prefecture. |
| 1934 || The Kawashizaki plant was separated from Rikagaku Kogyo and the Riken Piston Ring Co. was established with a capitalization of ¥1,600,000. |
| 1938 || The Riken Piston Ring Co. manufactured various machinery, measuring instruments, special steel and tools, as well as piston rings. The company merged with Riken Special Steels Co. and the name was changed to Riken Heavy Industries Co. which had a capitalization of ¥30,000,000. |
| 1939 || A plant was constructed in Kumagaya, Saitama Prefecture to manufacture piston rings for automobiles and airplanes. |
| 1941 || Riken Heavy Industries Co. merged with Riken Rolling Industries Co., Riken Forging, Riken Machine Tools Co., Riken Steel Co., Riken Foundry Co. and Rikagaku Kogyo, companies of the RIKEN Konzern, and changed its name to RIKEN Industries Co. The company had 26 plants and was capitalized at ¥70,000,000. |
| 1942 || Piston rings were successfully manufactured using an ERU type electric furnace. This was the first melting of cast iron in an electric furnace in Japan. |
| 1945 || All plants stopped operation at the end of the Second World War. A manufacturing license was obtained from GHQ to make automobile piston rings, cast iron products and agricultural equipment to establish peacetime industrial operation. |
| 1948 || The manufacture of TOP brand fittings began. |
| 1949 || The Riken Industries Co. was separated into 11 companies. Two of these were relaunched as Riken Kashiwazaki Piston Ring Industries Co. (capitalized at ¥20,000,000) and Riken Kumagaya Cast Iron Co. (capitalized at ¥10,000,000). |
| 1950 || Riken Kashiwazki Piston Ring Industries Co. became Riken Piston Ring Industries Co. |
| 1951 || Riken Kumagaya Cast Iron Co. became Kumagaya Cast Iron Co. |
| 1953 || Riken Piston Ring Industries Co. and Kumagaya Cast Iron Co. merged. |
| 1956 || Awarded the Okochi Commemorative Production Award by the Okochi Commemorative Association for "Improvement of Mass Production Methods for Piston Rings." The company applied for a manufacturing patent for a high ductility aluminum steel alloy ( alloy). |
| 1957 || Entered into a technical tie-up with the Shaw Process Co. of the U.K. for the Shaw process, a precision casting method. |
| 1958 || Started the manufacture and sale of LA couplings. The company began to manufacture and sell electric resistance materials in alloys (heating wire, heat resistant structural materials and electric resistance materials) under the PYROMAX brand product name. |
| 1961 || Entered into a technical tie-up with Hastings Corp. of the U.S. for a steel oil ring assembly (under the RIK-VENT product name). |
| 1964 || The 3 International Shaw Process Conference was at the Riken Central Research Center. Patents were obtained in various countries for RIK-HISIAL, a wear resistant aluminum alloy. |
| 1968 || Established Taiwan Riken Ind. Co., a joint venture with Yuen Foong Group to manufacture and sell piston rings, cylinder liners, and cylinder blocks in Taiwan. |
| 1970 || Introduced technology for LUCAS incineration equipment from the U.K. |
| 1973 || Established Siam Riken Ind. Co., Ltd. a joint venture with Siam Motor Co., to manufacture and sell piston rings in Thailand. |
| 1974 || Established Riken of America, Inc. to sell piston rings etc. in the United States. |
| 1975 || Capitalization increased to ¥ 3.5 billion. Began the manufacture and sale of PYRORIK industrial furnaces.
Established P.T. Sri Riken Vigna Indonesia (The corporate name has been changed to P.T. Pakarti Riken Indonesia.),a joint venture with Meiwa
Began the manufacture and sale of sintered alloy valve seat for lead-free gasoline. |
| 1976 || Began the manufacture and sale of MR JOINT stainless pipe fittings. |
| 1977 || Commenced operation of an automatic machining line for piston ring production operation. |
| 1978 || Established an operation to manufacture and sell 13 million piston rings per month, the third largest in the
world. Completed the startup of a RIKEN LUCAS fluid bed furnace with a drying stage. Exports reached a
record 13.8% of production. |
| 1979 || The corporate name was changed to Riken Corporation. Celebrated the 30th anniversary of its founding. |
| 1980 || Awarded the Okochi Commemorative Production Award by the Okochi Commemorative Association for "Development of an automatic machining line for piston ring production operation". |
| 1981 || Established an operation to manufacture and sell 17.5 million piston rings per month, the second largest operation in the world. Capitalization was increased to ¥ 4.2 billion. |
| 1983 || Completed the construction of the Tsurugi plant, a plant that would focus on steel ring production.
Established Euro-Riken GMBH to sell piston rings etc. in Europe. |
| 1986 || Established Shriram Pistons & Rings Ltd., a joint venture with Shriram Automotive Products Ltd., to manufacture and sell piston rings in India. |
| 1988 || Established Riken of Korea Inc., a joint venture with Korea Riken Industries Co. to manufacture and sell piston rings in Korea. |
| 1989 || Established Allied Ring Corporation, a US-based joint venture with Sealed Power Corporation, to manufacture and sell piston rings in America. |
| 1990 || Capitalization increased to ¥ 6.1 billion. |
| 1992 || Constructed a R&D center in Kumagaya.
Began the manufacture and sale of Riflon, seal rings for hydraulic equipment. |
| 1994 || Received the TPM Award for Excellence (Kumagaya and Kashiwazaki)
Entered into a technical tie-up with Intermet Corporation for the production of cast iron products.
Entered into a technical tie-up with Grede Foundries Inc., for the production of cast iron products. |
| 1996 || Capitalization increased to ¥ 7.9 billion. |
| 1997 || Obtained ISO 9001 certification (Piston Ring Department)
Dana Corporation acquired Sealed Power Division and assumed a position as Riken's joint venture partner in Allied Ring Corporation.
Capitalization increased to ¥ 8.5 billion. |
| 1998 || Began the sale of high frequency pyramidal ferrite absorbers. |
| 1999 || Obtained QS 9000 Certificates (Piston Ring Department). Celebrated the 50th anniversary of its founding.
Entered into a technical tie-up with Dana-Albarus for the production of piston rings in Brazil for Volkswagen Brazil. |
| 2000 || Signed a memorandum of understanding related to a global piston ring alliance with Dana Corporation .
Redenmption and retirement of treasury stock(1999-2000, 3.47 million stocks)
Began the manufacture and sale of SUS-FIT stainless pipe fittings. |
| 2001 || Obtained ISO 14001 certifications (Kashiwazaki and Kumagaya). |
| 2002 || Established a call center for pipe-fitting business. |
| 2003 || Siam Riken Ind. Co., Ltd. opened new piston ring plant and began production.
Established Jakarta Representative Office.Obtained Q1 Certification from Ford Motor Co. |