Continuing to Create the Essential Internal Grinders, Guided by Our Principle of “Unwavering Precision.”
Corporate Philosophy
We continue to create internal grinding machines that are essential, no matter the time or place, guided by our core principle of “unwavering precision.”
Message from the President
Inheritance and Innovation of Technology, and a New Stage Ahead
Irino Machinery Co., Ltd. embarked on a new journey in March 2020 by inheriting the business of the former Yamada Koki, a company that had produced outstanding internal grinding machines for 70 years. The exceptional technology and craftsmanship cultivated over the decades have been passed down to us and continue to be refined.
As we enter our sixth year since establishment, we are accelerating our growth and taking on new challenges. In July 2025, we will open a new headquarters at Yokosuka Research Park, expanding our technological development base. This will allow us to pursue even more advanced manufacturing and continue evolving toward the future.
We sincerely appreciate the customers, partner companies, and every employee who has supported us on this journey. It is thanks to your support that we have come this far. We will continue to uphold our gratitude and strive to provide even higher-quality products and services.
Carrying tradition into the future, and to the world.
Irino Machinery will pioneer new possibilities in manufacturing through the power of innovation.
February 2025
Irino Machinery Co., Ltd.
CEO Noriko Irino
Our History
For troubleshooting and repair requests, please contact us here.
Our dedicated support team will respond promptly and assist in maintaining your product in optimal condition.
The Birth of Irino Kiko
Irino Kiko Co., Ltd. is a manufacturer of machine tools that combines tradition and innovation.
In 2020, we took over the internal grinder manufacturing business from Yamada Koki Co., Ltd., which has produced over 3,000 units. We now manufacture precision internal grinders at our factory in Yokosuka, Kanagawa.
Technological Innovation and Contribution to Society
Our technology is essential for the manufacturing of precision components in a wide range of industries, from automotive to aerospace. Our relentless pursuit of excellence and innovation in product design continues to ensure the precision and rigidity of our products, delivering trust and peace of mind.
Passing on Technology and Talent
Despite the challenges posed by an aging population and declining birth rates, we are committed to passing on our technical expertise and nurturing the next generation of engineers who will support Japan’s future. We actively promote knowledge-sharing and mentoring from experienced craftsmen to younger engineers, creating an environment where free thinking and creativity are encouraged, without the barriers of age or position.
Vision for the Future
We are committed to continuous challenges. We will leverage the skills and experience we have built to keep producing high-quality products. We will also adapt flexibly to market trends both domestically and internationally, continuing to manufacture internal grinders in Yokosuka that everyone can use with confidence.
Towards the Realization of a Circular Society
Our remanufacturing program, started in 2020, involves disassembling used machines made by our company (and Yamada Koki), sorting and cleaning reusable cast materials, and using only parts that meet our internal standards to remanufacture the machines.
Our remanufactured machines are produced using the same processes and on the same floor as new machines, resulting in a remanufactured machine that offers the same or even better precision than the original product.
Our remanufactured machines are eligible for certification by the Japan Machine Tool Builders’ Association.
Company Overview
| Company Name | Irino Kiko Co., Ltd. |
| Established | March 16, 2020 |
| Capital | 10 million yen |
| CEO | Noriko Irino |
| Director | Yumiko Sugai |
| Director, Factory Manager | Katsutoshi Yamagata |
| Director, Sales Manager | Hiroaki Takeuchi |
| Technical Advisor | Shigeaki Mitsuhashi |
| Location | [Headquarters] 2-4-16 Ryoke, Kawaguchi City, Saitama, 332-0004, Japan [Factory] 1-3-23 Uchikawa, Yokosuka City, Kanagawa, 239-0836, Japan |
| Contact | Phone. 046-874-7444 Fax. 046-874-7911 |
| Business Activities | Manufacturing, sales, and repair of internal grinders and spindles |
| Banks | Takino-gawa Credit Union, Yahei Branch Bank of Yokohama, Kitakurihama Branch |
| Fiscal Year End | December 31 |
| Website | https://irinokiko.co.jp/ |
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Headquarters Map
Factory Map
Business Hours: Weekdays 8:30 AM - 5:15 PM / Closed on weekends and public holidays