MRO Magazine

Minebea Achieves GUINNESS WORLD RECORDS® Title of World’s Smallest Steel Ball Bearing on Market

August 31, 2015
By Business Wire News


Minebea Co., Ltd. announced today that its steel ball bearing was awarded the GUINNESS WORLD RECORDS title of smallest commercially available steel ball bearing on August 28, when a representative from Guinness World Records Ltd. certified its outer diameter at just 1.4978mm.

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(From left) Six engineers from the Karuizawa plant; Yoshihisa Kainuma, Representative Director, Pres ...

(From left) Six engineers from the Karuizawa plant; Yoshihisa Kainuma, Representative Director, President and Chief Executive Officer of Minebea; Erika Ogawa, Vice President of Guinness World Records Japan K.K. (Photo: Business Wire)

Yoshihisa Kainuma, Representative Director, President and Chief Executive Officer of Minebea, said: “We are really delighted to learn that our miniature ball bearing, a cornerstone of Minebea, was certified as the world’s smallest mass-produced steel ball bearing by GUINNESS WORLD RECORDS. This achievement can be attributed to the unfailing efforts of our engineers and all others involved in the product. Minebea’s mission statement—Passion to Exceed Precision—entails two meanings: a passion for achieving further precision and another passion for embarking toward uncharted territories. This award embodies the former passion. We will redouble efforts to create even more products that enrich people’s lives.”

Ikuko Koyama from the Karuizawa plant said: “The ball bearing’s 1.5mm external diameter was achieved thanks to our team’s efforts throughout the production process. I am really excited that bearings, which are often overlooked, are getting their chance in the spotlight. We boldly attempted to miniaturize bearings to a size never before seen and were able to bring them to market. It’s made me realize that hard work pays off and there is nothing that cannot be achieved.”


Minebea’s predecessor, Nippon Miniature Ball Bearing Co., Ltd. was established in 1951 in Tokyo as Japan’s first specialized manufacturer of miniature ball bearings, a market that has grown as many products trended towards lighter, thinner and smaller designs. Today, Minebea captures a worldwide market share in excess of 60% of ball bearings up to 22mm in external diameter—Japanese Industrial Standards (JIS) model number 608—according to its own research.

Minebea has long sought to demonstrate its ability to produce the tiniest mass-produced bearing in the world. In 2009, it successfully broke the 2mm barrier to pave the way for this ultra-small ball bearing.

The dimensions of this record-breaking bearing are 1.5mm in external diameter, 0.5mm in inner diameter, and 0.65mm in width, with six steel balls and supporting retainers. Despite its compactness, the precision complies with the JIS code. The company remains committed to producing new technologies that leverage its precision component expertise to benefit society.

Uses for ultra-small ball bearings

The record-breaking ball bearings are used in the tourbillon mechanism in the highest-grade mechanical watches in Japan. The design, development and manufacture of tourbillon mechanisms are considered one of the most difficult parts of watchmaking. Their delicate axels were traditionally supported by jewels such as ruby, but Minebea’s miniature ball bearings are small enough to be used for an application considered epoch-making among the independent watchmakers in Switzerland. This has opened up a new market for the company, with the potential for wider use and more applications.

Minebea is first record-holder recognized by the Takumi Nippon Project

The Takumi Nippon Project is supported by Guinness World Records Japan K.K. to stimulate and incentivise engineers, researchers and craftspeople in Japan. It recognizes their insatiable intellectual curiosity and challenging spirit and works to communicate it to the world. Minebea’s ball bearing is the first record-breaker to be recognized by the project for demonstrating Japan’s superior industrial technologies to the world.


About Minebea

Company name   Minebea Co., Ltd.
Head office 4106-73 Oaza Miyota, Miyota-machi, Kitasaku-gun, Nagano
Representative Yoshihisa Kainuma
Representative Director, President and Chief Executive Officer
Principal business line Machinery components business including ball bearings, Electronic devices and components business including electric devices and small-sized motors
Paid-in capital 68,258 million yen (as of March 31, 2015)
Established July 1951
Financial closing date March 31
Major shareholders and shareholding ratio The Master Trust Bank of Japan, Ltd. (Trust Account): 7.64%
Japan Trustee Services Bank, Ltd. (Trust Account): 5.51%
Takahashi Industrial and Economic Research Foundation: 4.08%
(as of March 31, 2015)
Total net assets (consolidated) 233,679 million yen (as of March 31, 2015)
Total assets (consolidated) 490,043 million yen (as of March 31, 2015)
Net sales (consolidated) 500,676 million yen (fiscal year ended March 31, 2015)
Number of employees   Non-consolidated: 3,853 (as of June 30, 2015)
Consolidated: 67,466 (as of June 30, 2015)

GUINNESS WORLD RECORDS® is a registered trademark of Guinness World Records Ltd.

For media inquiries, please contact:
Minebea Co., Ltd.
Mr. Yasuo Komine, +81-3-6758-6703
General Manager
Corporate Communications Office
For more information on the company’s wide range of products, please visit its website: