- September 1905
- Kobe Seikosho (Kobe Steel Works) is founded by Suzuki Shoten, a general partnership company. The company is incorporated in 1911.
Kobe Steel soon after its foundation
- August 1915
- Machinery business begins
Kobe Steel makes Japan's first air compressor.
- August 1916
- Steel products business begins
Kobe Steel starts producing rolled steel products.
- December 1917
- Copper business begins
Kobe Steel starts production of copper tube and bar.
- April 1926
- Engineering business begins
Kobe Steel completes Japan's first cement plant for Nippon Cement. The Saeki Plant has an annual capacity of 450 metric tons.
Cement machinery circa 1923
- September 1930
- Construction machinery business begins
Kobe Steel produces Japan's first electric mining shovel.
Japan's first electric shovel, the 50K
- February 1937
- Aluminum business begins
The Nagoya Plant starts production of aluminum castings and forgings. In 1939, the Chofu Plant begins production of aluminum rolled products.
Chofu Plant under construction.
- July 1940
- Welding business begins
Kobe Steel produces Japan's first welding electrodes.