Aalborg Industries Co., Ltd.
Haneda Pipe Works Co., Ltd.
Hitachi Shipbuilding & Engineering
Gadelius
Innoshima Boiler Co., Ltd.
Ishikawajima-Harima Heavy Industries Co., Ltd.
Ishikawajima Ship & Chemical Plant Co., Ltd.
Kawasaki Heavy Industries, Ltd.
Kikan Buhin Seizosho Co., Ltd.
Kobe Steel Ltd.
Mitsubishi Heavy Industries, Ltd.
Mitsui Shipbuilding Engineering Co., Ltd.
Miura Kogho Co., Ltd.
Nippon Kokan
Nishida Marine Boiler
Osaka Boiler
Sasakura
Takuma
Tortoise Engineering
Volcano