NKK Kawasaki Steel Works (Nippon Kokan)

Nippon Kokan Kabushiki Kaisha (日本鋼管株式会社, NKK) was established on June 8, 1912, by Motojiro Shiraishi with backing from the Asano zaibatsu. The company was founded in the Watarida district of Kawasaki City, Kanagawa Prefecture, with the mission of manufacturing Japan's first domestically produced seamless steel pipes. Commercial production began in April 1914 with a 20-ton open-hearth furnace, and NKK quickly expanded beyond pipes to produce steel bars, heavy plates, and steel sheets.

Located at the heart of the Keihin Industrial Zone — Japan's largest and most strategically important industrial corridor stretching between Tokyo and Yokohama — the Kawasaki works grew rapidly during the interwar period. In 1936, NKK completed its first blast furnace at the Ogimachi plant in Kawasaki, achieving integrated steelmaking capability. By the late 1930s, NKK had become one of Japan's leading steel producers outside the government-controlled Nippon Steel consortium, deliberately maintaining its independence as an "outsider" (アウトサイダー) company.

During World War II, NKK's Kawasaki facilities were mobilized for total war production. The works produced thick armor plate, seamless steel tubes for gun barrels, ship hull plating, and other military-grade steel essential for the Imperial Japanese Navy's warship construction program. In 1940, NKK merged with the Tsurumi Steelmaking and Shipbuilding Company (formerly Asano Shipbuilding), adding shipbuilding capacity. A 5,000-ton shipbuilding berth was completed at the Shimizu yard in 1943. NKK's first Pilger Mill, built in Watarida in 1943, enabled production of large-diameter seamless pipes critical for naval vessels and heavy artillery.

As a major component of the Keihin Industrial Zone, the Kawasaki works became a prime target for the U.S. strategic bombing campaign. Beginning in late 1944, the Keihin industrial corridor suffered devastating B-29 incendiary raids. The Kawasaki area was hit particularly hard during the great Tokyo-Yokohama firebombing raids of April and May 1945. By war's end, NKK's rolling mills and steelmaking facilities were severely damaged, with only a fraction of capacity remaining operational. Company president Ryozo Asano, in office since 1942, stepped down in 1946.

Post-war reconstruction began under new leadership in 1946. NKK rebuilt its Kawasaki works, installed some of Japan's earliest pure oxygen converters (1958), and in 1971 began constructing an entirely new integrated steelworks on the reclaimed Ogishima (扇島) artificial island in Kawasaki harbor. The Keihin works today operates as JFE Steel Corporation's East Japan Works (Keihin District), continuing to produce thick plate, thin plate, surface-treated steel, and steel pipe — a direct descendant of the wartime arsenal that once armed the Imperial fleet.