1907	Founded as a joint venture by three companies-Hokkaido Colliery Steamship Company of Japan, Armstrong Whitworth Co.,Ltd.,UK, and Vickers Sons and Maxim, Ltd.,UK.
1915	Headquarters are transferred to Tokyo.
1919	Merged with Hokkaido Steel & Iron Company　Started the business of mining and iron-making
1931	Separated the above-said business
1945	Started civil goods production
1950	The Japan Steel Works, Ltd. is dissolved and reestablished.
1973	Granted ASME U and U2 Certificates
1974	Granted ASME NPT Certificate(QSC in 1975)
1983	Awarded the Deming Prize
1994	Granted ISO 9001, 9002 Certificates
1998	Granted ISO 14001 Certificate
2002	Granted ISO 9001 Certificate(9001 and 9002 combined)
2003	Renewal of 10,000-ton press to maximum capacity of 11,000 tons (14,000-ton maximum deposit)
2007	The company marks the centenary year of its founding. The headquarters is moved to Osaki in Tokyo.
2009	Granted OSHMS Certificate
2011	Produced the 670-ton steel ingot (world's largest)
2019	Granted ASME U3 Certificate
2020	Japan Steel Works M&E is established. 　Steel and Energy Products Business and Wind Power Equipment Maintenance Service Business as well as four group companies of JSW were integrated into the newly established subsidiary.