| 1925 |
Establishment of Ogaki Electric Metallurgy Works (later Nippon Electric Metallurgy Co., Ltd.), manufacturing and sales of various alloy irons |
| 1935 |
Incorporation and establishment of Denki Metallurgy Works Co., Ltd. (later Nippon Electric Metallurgy Co., Ltd.) |
| 1936 |
Renamed to Nippon Electric Metallurgy Co., Ltd. |
| 1937 |
Start of chromium salt manufacturing and sales in Kuriyama, Hokkaido |
| 1949 |
Listed on the Tokyo Stock Exchange |
| 1963 |
Merged with Toho Denka Co., Ltd. to establish Nippon Denko Co., Ltd. |
| 1969 |
Construction and operation start of Tokushima Factory (equipped with port facilities and large electric furnaces) |
| 1973 |
Start of chromium acid recovery business |
| 1984 |
Start of ferrobromon manufacturing and sales using electric furnaces |
| 1989 |
Start of zirconium oxide manufacturing and sales |
| 1992 |
Completion of new chromium acid recovery plant in Koriyama |
| 1993 |
Established South Africa Samanco Co. and NST Ferrochrome Co. (withdrew from business in 2012 after share sale) |
| 1996 |
Start of Aqua Pack cartridge-type pure water purifier sales |
| 1999 |
Start of MR Pack pure water system sales |
| 2000 |
Strategic partnership with South Africa's Samanco and Ferro Manganese |
| 2000 |
Completion of Ferroboron manufacturing equipment enhancement project |
| 2000 |
Completion of boron oxide recovery equipment construction project |
| 2000 |
Completion of new zirconia oxidation plant |
| 2001 |
Strategic partnership with Nippon Rensui Co., Ltd. (now Mitsubishi Chemical Aqua Solutions Co., Ltd.) |
| 2002 |
Establishment of South Africa's High Belt and SAJ Vanadium (withdrew from business in 2017 after share sale) |
| 2002 |
Establishment of ND Recycling Co., Ltd. (withdrew from business in 2017 after share sale) |
| 2002 |
Started nickel recovery and resource recycling business |
| 2003 |
Acquired lithium manganese secondary battery materials business |
| 2004 |
Started fluorine recovery business |
| 2004 |
Started delivery of pure water equipment for fuel cells |
| 2005 |
Installation of electric furnace gas utilization cogeneration equipment at Tokushima plant |
| 2008 |
Enhanced production capacity of low-carbon ferro manganese (SLP) (30,000 tons/year) |
| 2009 |
Established a system for high-carbon ferro manganese with annual production of 220,000 tons |
| 2010 |
Completed first phase large-scale factory for automotive battery materials |
| 2010 |
Further increase in low-carbon ferro manganese (SLP) production capacity (40,000 tons/year) |
| 2011 |
Completed second phase large-scale factory for automotive battery materials |
| 2012 |
Transferred chromium salt business to Nippon Chemical Industrial Co., Ltd. |
| 2012 |
Invested in Pertama Ferroalloys Sdn. Bhd. |
| 2013 |
Announced management integration with Chuo Electric Industrial Co., Ltd. |
| 2013 |
Acquired manganese mine rights in South Africa |
| 2014 |
Obtained certification for renewable energy fixed-price purchase system (FIT) facilities |
| 2016 |
Transferred alloy business for magnets to Santoku and Sojitz |
| 2017 |
Horumangawa Second Power Plant Reoperation |
| 2018 |
Fully integrated with Chuo Electric Industry Co., Ltd. |
| 2018 |
Operation of Incineration Ash No.3 Melting Furnace (EM3) |
| 2019 |
Horumangawa Third Power Plant Reoperation |
| 2021 |
Red brick building (Myoko Factory) registered as a tangible cultural property |
| 2021 |
Capacity expansion of facilities for oxidized boron and zirconium oxide |
| 2021 |
End of alloy steel production at Kashima Factory |
| 2022 |
Solar power generation facility operational |
| 2022 |
Operation of Incineration Ash No.4 Melting Furnace (EM4) |
| 2024 |
Absorbed and merged with Chuo Electric Industry Co., Ltd. |
