| Dec. |
1908 | |
Sobo Marine Products K.K. was established by Showa Denko (SDK) founder, Nobuteru Mori, to manufacture and sell iodine in Chiba Prefecture. Sobo Marine Products subsequently developed into Nihon Iodine K.K. |
| Oct. |
1926 | |
Nihon Iodine K.K. was establilshed. |
| Apr. |
1928 | |
Showa Fertilizers K.K. was established. |
| Mar. |
1934 | |
Nihon Iodine K.K. was renamed as Nihon Electrical Industries K.K. |
| Jun. | 1939 | |
Nihon Electrical Industries and Showa Fertilizers merged to form Showa Denko K.K. |
| May. | 1949 | |
SDK was listed on Tokyo Stock Exchange. |
| Sept. | 1951 | |
SDK was awarded the first Deming Prize. |
| Apr. | 1969 | |
Oita Petrochemical Complex started commercial operation. |
| Mar. | 1977 | |
Second expansion project of ethylene production capacity was completed at SDK Oita Petrochemical Complex. |
| Feb. | 1986 | |
SDK withdrew from its domestic aluminum smelting business. |
| Nov. | 1989 | |
Hard Disk Plant No. 1 was completed at Chiba. |
| Jan. | 1995 | |
Omachi Works obtained ISO 9001 certification. |
| May. | 1997 | |
Production Technology Center obtained ISO 14001 certification. |
| Mar. | 2001 | |
SDK merged with Showa Aluminum Corporation. |
| Sept. | 2003 | |
Japan Polyolefins Co., Ltd. and Japan Polychem Corporation integrated the polyethylene businesses and established a new joint venture company. |
| Jul. | 2004 | |
Trace Strage Technology Corp., become a consolidated subsidiary. |
| Nov. | 2004 | |
SDK announced to produce high-power blue LED chips. |
| Mar. |
2005 |
|
SDK sold shares in SDS Biotech K.K. via MBO scheme. |
| Jul. |
2005 |
|
SDK started production of world's first perpendicular magnetic recording technology HD media. |
| Jan. |
2006 |
|
SDK satarted its new medium-term consolidated business plan "PASSION Project" for the 2006-2008 period. |
| Sept. |
2006 |
|
SDK satarted up new aluminum cylinders plant in Oita. |
| Dec. |
2006 |
|
SDK opened its new hard disk media plant in Singapore. |
| Feb. |
2007 |
|
SDK develops new crystal growth technology for GaN-based blue/white LEDs. |
| Sept. |
2007 |
|
SDK opened its second neodymium-based alloys plant in China. |
| Jun. |
2008 |
|
Showa Tansan Co., Ltd. become a consolidated subsidiary. |
| Jul. |
2010 |
|
SDK merged with Showa Highpolymer Co.,Ltd. |
