| April 1897 |
Sumitomo Copper Rolling Works was opened in Osaka to start copper rolling business |
| 1898 |
Launched aluminum rolling business |
| June 1913 |
Corporate name changed to Sumitomo Copper Works |
| Feb. 1921 |
Incorporated as Sumitomo's Copper-rolling Works |
| July 1926 |
Reorganized as Sumitomo Steel Tube & Copper Works, renaming its factory in Ajigawa (Osaka City) as Copper Works |
| Nov. 1928 |
Moved Copper Works to a new factory built in Sakurajima, Osaka City |
| Oct. 1935 |
Sumitomo Steel Tube & Copper Works merged with Sumitomo Steel Works Co., Ltd. to incorporate Sumitomo Metal Industries Co., Ltd. |
| Sep. 1941 |
Built Nagoya Light Alloy Works in Nagoya |
| May 1947 |
Renamed Nagoya Light Alloy Works as Copper Works |
| Aug. 1959 |
Sumitomo Light Metal Industries Co., Ltd. was spun off from Sumitomo Metal Industries, formed by its copper products and aluminum rolling divisions. Operation started in September |
| Jan. 1962 |
To change the face value of its stock to \50 per share, SLMI merged with a corporation which was also named "Sumitomo Light Metal Industries Co., Ltd.". (The merger partner, which was originally founded as Maruni Shokai Co., Ltd. on March 29, 1951, renamed itself in Sep. 1961.) |
| Jun. 1966 |
Started operation of new equipment for aluminum hot rolling |
| Mar. 1969 |
Built the most up-to-date copper tube factory for the time at an affiliate Sumikei Copper Industries Co., Ltd. (Ichinomiya-cho, Hoii County., Aichi Pref.) in an attempt to expand the wrought copper business. |
| May 1969 |
Built Chiba Works in Kashiwa City, Chiba Pref. |
| Feb. 1973 |
Founded Sumikei Aluminium Industries Co., Ltd. (disorganized in May 1982), planning to build a refinement-to-rolling plant in Sakata Seaside Zone, Yamagata Pref. |
| Oct. 1975 |
Established Technical Research Laboratories |
| May 1979 |
Founded Sumikei Aluminum Foil Co., Ltd. |
| Aug. 1979 |
Founded SLM Australia to participate in Comalco Limited's aluminum refinery project in Gladstone, Australia |
| Apr. 1984 |
Founded Sumikei Memory Disc Co., Ltd. (disorganized in Sept. 1999) |
| Apr. 1985 |
Mergered with Sumikei Copper Industries Co., Ltd., renaming its mill as Copper Works |
| Oct. 1988 |
Mergered with Sansen Real Estate Co., Ltd. |
| Feb. 1990 |
Founded Sumikei Malaysia Sdn. Bhd. |
| Jun. 1991 |
Mergered with Nagoya Kosan Co., Ltd. |
| Sep. 1991 |
Founded Sumikei Engineering Co., Ltd. |
| Oct. 1991 |
Mergered with Nagoya Kosan Co., Ltd. |
| Mar. 1993 |
Completed modernization of Nagoya Works's aluminum rolling capacity |
| Aug. 1995 |
Founded Sumikei Memory Disc Malaysia Sdn. Bhd. |
| Nov. 1995 |
Founded Sumikei (Guangzhou) Metal Products Ltd. |
| Oct. 1998 |
Mergered with Sen-nen Kosan Co., Ltd. and Sumikei PD Warehouse Co., Ltd. |
| Sep. 1999 |
Withdrew from domestic memory disc business |
| Apr. 2000 |
Mergered with Sumikei Technos Co., Ltd. |
| Aug. 2000 |
Founded Sumikei Engineering Co., Ltd jointly with Nippon Light Metal Company |
| Aug. 2000 |
Discontinued the operation of Sumikei Memory Disc Malaysia |
| Dec. 2000 |
Reached agreement on cooperation with Kobe Steel |
| Oct. 2002 |
Founded Sumikei Techno Czech s.r.o. |
| Oct. 2003 |
Founded Izumi Metal Co., Ltd. (distribution integration) |
| Jan. 2004 |
Launched New Medium-term Business Plan |
| Apr. 2004 |
Implemented business integration with Toyofitting Co., Ltd. |
| Apr. 2005 |
Founded Shinsen Aluminium Co., Ltd. |
| Apr. 2006 |
Founded Sumikei Doukan Hanbai Co., Ltd. |
| Oct. 2006 |
Disorganized Sumikei Kakou Mfg. Co., Ltd. |
| Mar. 2007 |
Launched Plan 2010 (the 3rd Medium-term Business Plan) |
| Apr. 2007 |
Transferred the business of Nippon Trex Co., Ltd. |
| Aug. 2007 |
Completed modernization of Nagoya Works's extrusion capacity |
| Oct. 2007 |
Transferred the business of Shin Nitto Metal Industry Co., Ltd. |
| Oct. 2009 |
Founded Nippon Aluminium Group |
| Apr. 2010 |
Founded Sumikei Techno Group |
| Act. 2011 |
Founded Sumikei Copper Tube Co., LTD. |
