Site:               Toshiba Corporation, Mie Works
                    2121 NA Asahi-Cho
                    Mie Prefecture 512, Japan
Date Visited:       January 9. 1996

WTEC Attendees:     D. Bertram (report author), D. Apelian, G. Holdridge

Hosts:              Masaharu Tamiya, Manager of Manufacturing Engineering Staff
                    Yoshiatsu Sato, Senior Manager, Casting Department


Toshiba's reported FY 1994 sales were ¥4.8 trillion, also reported as $54 billion. This is a multi-national company with 190,000 employees. Business segments include communications, consumer electronics and appliances, power systems, industrial equipment, and electronics.

The Mie Works is a gray iron foundry producing motor frames for Toshiba's wide range of industrial motor sizes. It also produces air conditioning compressor castings and large electric motor aluminum rotor castings with a low pressure process. It is the only gray iron foundry operated by Toshiba.

Nearly 90% of production is for Toshiba products, with the remaining 10% sold directly to outside customers (mostly automotive air conditioner compressor parts). Approximately 70% of the internal volume is for motors and 20% for home air conditioning compressors.

At the time of the WTEC visit, this plant was producing 900 tons of small motor parts and 450 tons of compressor components for air conditioners each month.

The Mie plant was established in 1938, employs about 2,200 people, and has about 187,000 m2 of floor area.


Melting is by cupola and coreless electric furnaces. Mold lines are automated cope and drag machines. Pouring is manual.

Mie management is planning to implement a plant-wide local area network (LAN). It will facilitate on-line control.

Training is a key manufacturing focus and is considered more important than recruitment efforts. Continuous retraining is considered extremely important in maintaining Mie's two-year-old International Standards Organization (ISO) 9000 certification.

Toshiba Corp. has a goal of reducing its waste stream by 50% and doubling its energy efficiencies in five years. The Mie plant has already reduced its waste stream by over 50% (from 350 tons/month to 100 tons/month) and has a target of cutting it by another 50 tons/month.

The allowance for capital spending is ¥150 million, 30% of which is earmarked for environmental protection. More money is available for justified energy reduction projects.

Toshiba does not degas the melt unless required for a special product. In that case, magnesium is used for degassing.

Emphasis from the parent company is on cost reduction rather than on improving the product since Toshiba already has very high efficiency motors. One Toshiba innovation yields higher efficiency motors by casting cooling fins on rotors between magnets and by combining motors and inverters in same unit.

In the future, Toshiba managers see evaporative casting technology as potentially a low cost process for motor frame castings.

The managers of the Mie works do not consider aluminum frames a threat to gray iron.


The foundry has little involvement with frame design unless some final product modifications are suggested to enhance the moldability or lower the production cost.

Research and Development efforts are mainly with analysis of process flow in cooperation with Prof. Niyama at Tohoku University well as with Prof. Ohnaka at Osaka University. A current in-house R&D project involves a nickel alloy gray iron having a lower coefficient of thermal conductivity and expansion (1/5 the conductivity of normal gray iron). The Mie staff is now looking for a product application.


The products of the Mie works are under extreme pricing pressure. Emphasis at the plant level is on reducing energy consumption and environmental costs.

Published: March 1997; WTEC Hyper-Librarian