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Toshiba Materials Makes Major Investment to Expand Silicon Nitride Bead Production Capacity

YOKOHAMA, Japan–(BUSINESS WIRE)–Toshiba Materials Co., Ltd. (Chairman: Katsuaki Aoki) today announced a major investment in a new silicon nitride bead manufacturing facility at the same site as its headquarters in Yokohama, Japan. The project has a budget of more than 5 billion yen (approximately $38 million) and is expected to see production start in November 2023. It will increase capacity by 50% from fiscal 2021.

Continuing advances in automotive electrification require solutions that go beyond high-voltage batteries and faster charging times. One measure to reduce costs and improve performance is the integration of motors and inverters. Although this increases the risk of electrolytic corrosion[1] in motor bearings[2], the problem can be overcome with hybrid bearings, which replace standard steel balls with ceramic balls with steel inner and outer rings. The advantages of high reliability, excellent strength and superior wear resistance are increasingly positioning ceramic balls as the solution of choice.

The Toshiba Group has long recognized the potential of fine ceramic products and obtained basic patents for silicon nitride compounds as early as 1974. Today, Toshiba Materials, spun off from Toshiba in October 2003, continues to advance R&D and the manufacture of silicon nitride balls, known for their reliability and for offering the highest mechanical performance of all silicon balls. Its experience and successes in ball bearings meeting high-speed rotation and electrolytic anti-corrosion requirements, including machine tools, wind turbines and rolling stock, have earned the company about 50% of the global market. .[3]. With significant increases in demand for EV bearings on the horizon, Toshiba Materials has now decided to make this significant investment in increased capacity.

The new production plant will be built on the site of the company’s headquarters, where an old building, now disused, will be demolished to make way for it. The new facility should be seen as the first phase of expansion, and Toshiba Materials is already considering further expansions to meet future growth in demand.

Toshiba Materials will maintain a stable supply of high-quality products and contribute to increased use of environmentally friendly electric vehicles.

Characteristics of silicon nitride beads

  • Low density: less than half the weight of a steel ball of the same size

  • High heat resistance

  • Resistant to electrolytic corrosion, as it is an insulator

  • Resistant to corrosion and rust caused by acids and alkalis

  • A non-magnetic material, not easily affected by strong magnetic field

1 Electrolytic corrosion: damage to a bearing caused by a current flowing through it.

2 Bearing: part that allows a shaft to rotate smoothly in a machine. Formed with an inner ring, balls and an outer ring.

3 Toshiba Materials survey, July 2022

About Toshiba Materials

Toshiba Materials Co., Ltd. ( was spun off from Toshiba Corporation in 2003. With materials design technology as its core capability, Toshiba Materials provides materials and components essential for the development of the society. The main products include metal materials, components, fine ceramic parts and chemical materials. In the fiscal year ended March 31, 2021, net sales totaled 24.3 billion yen (approximately $210 million).