|1935||Established Nakase Kogyo Co.,Ltd. to develop gold,silver,antimony minerals.|
|1936||Changed company name to Nihon Seiko Co.,Ltd.|
|1948||Constructed the smelting plant and started manufacturing and sales of antimony trioxide and antimony metal.|
|1952||Changed sources of raw materials from domestic mines to overseas supplies.|
|1955||Commenced manufacturing and sales of the catalyst grades of antimony trioxide.|
|1971||Commenced manufacturing sodium antimonate.|
|1976||Constructed desulfurration plant and started manufacturing and sales of gypsum.|
|1982||Started manufacturing and sales of PATOX-L (large particle size) and PATOX-U (small particle size).|
|1985||Constructed large scale reduction furnace.
Celebrated the 50th anniversary of the company.
|1986||Constructed large scale metal furnaces to produce PATOX grades.|
|1988||Increased company's capital to 1,018 million yen.|
|1991||Introduced automatic packing and storing system.|
|1992||Built new factory to accommodate the new special surface treatment facility.|
|1997||Completed new office building at Nakase.|
|1998||Completed new laboratory at Nakase.|
|2000||Nippon Atomized Metal Powder Corporation (Noda City, Chiba Prefecture) became a subsidiary of Nihon Seiko through the acquisition of the major portion of that company's issued stock.
Nihon Seiko Co.,Ltd. accredited with ISO14001.
|2003||Nihon Seiko Co.,Ltd. accredited with ISO9001.
Purchased the antimony business including some plant facilities of Sumitomo Metal Mining Co.,Ltd.
|2004||Completed production facilities of high purity antimony trioxide.|
|2008||Completed acquisition of 100% issued stock of Nippon Atomized Metal Powder Corporation|
|2009||Completed new technical center at Nakase|
|2012||Completed Tsukuba Plant, new plant of Nippon Atomized Metal Powder Corporation, in Ibaraki.|