Japan DROP Forge Co., Ltd.

Japan DROP Forge Co., Ltd. (日本鍛工株式会社) is a Japanese forging and machining company headquartered in Amagasaki, Hyogo Prefecture. Its origins trace to 1924, when Shinji Shibayanagi founded the Okajima Iron Works (恩加島鉄工所) as a sole proprietorship. The business was incorporated in 1934 and reorganized as Japan DROP Forge Co., Ltd. in 1937, with its head office in Tokyo and capital of 5 million yen. Over the following decades the company built a long record of supplying forged and machined components to the automotive, motorcycle and industrial machinery industries, and in 2024 it marked its 100th anniversary. The company describes itself as combining forging technology with machining technology to meet increasingly advanced product needs at high quality and low cost. Its product range includes machined parts, motorcycle parts, automobile parts, and parts for construction, agricultural and industrial machinery, as well as other forged products. It promotes near-net-shape forging — delivering forged parts in shapes close to the finished component — to help customers reduce machining costs, and it jointly develops new materials with Daido Steel Co., Ltd. Japan DROP Forge forms a three-company group with Daido Steel and Toyo Sangyo, sharing information and dividing roles by manufacturing scale and product type so that the best production method and proposal can be selected for each customer's needs. The company's history includes milestones such as becoming a designated factory of the Ministry of Railways in 1927, starting production of HAPPY-brand work tools in 1930, beginning transactions with Mitsubishi Motors in the early 1930s and with Mazda in 1936, and completing its Amagasaki plant (the current head office plant) in 1941. After World War II production halted in 1945 and the Amagasaki plant restarted in 1946. The company continues to operate as a forging specialist serving major Japanese manufacturers.

Japan DROP Forge Co., Ltd. traces its origins to November 1924, when Shinji Shibayanagi founded the Okajima Iron Works (恩加島鉄工所) as a sole proprietorship. In 1927 the works became a designated factory of the Ministry of Railways, and in 1928 it won a contract from Nihon Chisso for 100,000 electrode pins. In May 1929 a new 1,000-tsubo factory was built in Minami-Okajima-cho. Around 1930 the company began manufacturing HAPPY-brand work tools, and in the early 1930s it entered into transactions with Mitsubishi Motors. The Great Depression brought difficult management conditions in 1931. In April 1934 the Okajima Iron Works was reorganized into a corporation with capital of 2 million yen, and Shinji Shibayanagi became president. In August of that year he toured the forging industries of Europe and the United States. In April 1935 the Kanzaki plant was completed and the head office moved there, and the latest equipment was introduced from Europe and the United States. A Tokyo office was opened in August 1936, around which time transactions with Mazda began. In August 1937 Japan DROP Forge Co., Ltd. was established with Shinji Shibayanagi as president, headquartered in Tokyo with capital of 5 million yen; in September it merged with the Okajima Iron Works, raising capital to 7 million yen. In May 1938 the Kawasaki plant was completed to support the establishment of the automobile industry, and in September Nihon-Manchu Forge Co., Ltd. was established with capital of 5 million yen. In July 1939 the company was designated a jointly managed factory of the army and navy. In 1940 the Kawasaki plant was progressively converted to military production. In August 1941 the Amagasaki plant (the current head office plant) was completed, and the Kanzaki and Okajima plants were relocated there. In January 1942 Nihon Press Machine Co., Ltd. was established. In April 1945 construction of the Yamaguchi evacuation plant began, the Hadano plant came into full operation that spring, and the Nihon Forging Industrial Vocational School opened. In August 1945 production stopped with the end of the war, and in September a dissolution ceremony was held with 5,000 employees. In December the Kawasaki and Hadano plants were designated for reparations. In May 1946 the Amagasaki plant restarted operations. In the postwar decades the company continued to serve the automotive, motorcycle and industrial machinery sectors with forging and machining. Its official history is presented in period sections covering 1924–1946, 1948–1963, 1964–1976, 1977–1989, 1990–2002, 2003–2014 and 2015–2023. In the present day it emphasizes near-net-shape forging and joint development of new materials with Daido Steel, and it operates within a three-company group with Daido Steel and Toyo Sangyo that divides roles by manufacturing scale and product type. In 2024 the company celebrated its 100th anniversary.

• 2024

  Celebrated 100th anniversary.

• 1946

  Amagasaki plant restarted operations.

• 1945

  Production stopped at the end of the war; dissolution ceremony held with 5,000 employees; Kawasaki and Hadano plants designated for reparations.

• 1942

  Nihon Press Machine Co., Ltd. established.

• 1941

  Amagasaki plant (current head office plant) completed; Kanzaki and Okajima plants relocated there.

• 1939

  Designated a jointly managed factory of the army and navy.

• 1938

  Kawasaki plant completed; Nihon-Manchu Forge Co., Ltd. established.

• 1937

  Japan DROP Forge Co., Ltd. established with head office in Tokyo and capital of 5 million yen; merged with Okajima Iron Works, raising capital to 7 million yen.

• 1936

  Tokyo office opened; transactions with Mazda began around this time.

• 1935

  Kanzaki plant completed and head office moved there; latest equipment introduced from Europe and the United States.

• 1934

  Okajima Iron Works reorganized into a corporation with capital of 2 million yen; Shinji Shibayanagi became president.

• 1932

  Began transactions with Mitsubishi Motors around this time.

• 1930

  Began manufacturing HAPPY-brand work tools.

• 1929

  Built a new 1,000-tsubo factory in Minami-Okajima-cho.

• 1928

  Won a contract from Nihon Chisso for 100,000 electrode pins.

• 1927

  Became a designated factory of the Ministry of Railways.

• 1924

  Okajima Iron Works founded by Shinji Shibayanagi as a sole proprietorship.

High-quality, low-cost forging and machining supplier using near-net-shape technology and joint material development.

• Machined parts

• Motorcycle parts

• Automobile parts

• Construction, agricultural and industrial machinery parts

• Other forged products

1. 1日本鍛工株式会社 ｜ おかげ様で１００周年j-d-f.co.jp
2. 21924〜1946 | 日本鍛工株式会社j-d-f.co.jp
3. 3製品案内 | 日本鍛工株式会社j-d-f.co.jp
4. 4Japan DROP Forge Co., Ltd. (Japan) - Wikidatawikidata.org