The purpose of this paper is to analyze the medium-sized munitions companies which grew rapidly in the interwar period, focusing on Watanabe Tekkojo (Watanabe Engineering Corporation).
In 1886, Watanabe Tekkojo was established as the supporting section of a wholesale merchant of metal products in Fukuoka. It had expanded into munitions in 1902, when Fukuo Watanabe became one of the executives in the company. He had experience of working in the military section of Ishikawajima Shipbuilding & Engineering Co., Ltd. Watanabe Tekkojo made advances to the Imperial Japanese Navy in WW I, and received orders for parts of torpedoes and torpedo tubes from the navy. The orders increased after the Washington Naval Treaty. In the 1930s the navy built up military aircrafts because of the London Naval Treaty, so Watanabe Tekkojo began to manufacture parts of aircrafts.
In the past studies about the Japanese munitions companies, the military sections of the Zaibatsu Konzerns had attracted attention as the center of the private military companies. Accordingly, it has been defined that the military influence in the Japanese economy was reduced in the disarmament period before WW II. However, the Imperial Japanese Navy also made advance to the medium-sized companies. As a result, the range of the munitions industry was expanded in Japan. The Imperial Japanese Navy gave technical guidance to the medium-sized munitions companies, dispatched able engineers to them, helped the procurement of their capital and materials and so on.
The change in the interwar period led the Japanese military production system to the wartime economic controls in WW II. Aircrafts and the others munitions were made by not only arsenals and the Zaibatsu Konzerns but also many medium-sized munitions companies.