Creating Future: We constantly tackle challenges with our technical capabilities.

“Absolute trust” is the proof of our technical capabilities. Rigaku’s Magnetic Fluid Seals

The origin of Rigaku’s magnetic fluid seal units goes back to 1952 when Rigaku commercialized a rotating anode X-ray generator for the first time in the world.
Although they were originally the built-in units for in-house products, Rigaku Mechatronics was newly established in 1989 as a manufacturer of magnetic fluid seal units based on the technologies accumulated by that time.
Our products have been widely selected as a clean shaft bearing to solve various issues in the needs from customers who put the highest priority on reliability.

New products are available now.
These products are compatible with Ferrotec’s seals.
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The magnetic force and the magnetic fluid form a liquid-type O ring. What is a magnetic fluid seal?

A magnetic fluid seal, due to its characteristics of “long service life”, “Contamination-less”, “high vacuum performance / high pressure resistance”, and “high speed rotation”, has a higher performance than other general-purpose seals such as oil seals and it has been mainly used as a rotary seal unit in a vacuum system for semiconductors and FDP industries.

  • Long service life

    No contact between the rotary shaft and solid parts,
    No wear from friction

  • Contamination-less

    Liquid is used for the sealing material, so no particles will be generated from friction during rotation.

  • High vacuum performance / high pressure resistance

    Creating a magnetic circuit fixes the magnetic fluid into an o ring, providing a powerful sealing performance.

  • High speed rotation

    As the seal is formed with liquid, little torque is lost and high-speed rotation is enabled.

Advantages of selecting Rigaku’s magnetic fluid seals

We are a team specialized in magnetic fluid seals within the Rigaku Group, working with semiconductor industries for 30 years.


30 years of history in the field of magnetic fluid seals

We are a long-established manufacturer with the 30 years of history in manufacturing and development of magnetic fluid seals. We are confident that we can best any other company with the expertise we have accumulated over the past 30 years. Also, as we have never been satisfied with the status quo, we have implemented and will implement further research and development to upgrade our technologies.


Special-Order Products

Many of our products are special-order products for which dedicated drawings are created. According to our motto: “product development close to our customers”, we respond to various needs from a spot production for one unit to mass production, from the perspective of customers and with a strong sense of commitment. We always ask ourselves in our daily operations, “How can we provide products whose quality, cost and delivery are totally satisfactory to our customers?”


Rigaku Group

As we belong to the Rigaku Group specialized in X-ray analysis instruments, we are located within the premises of Rigaku. We can provide a proposal one step ahead of others, through heat analysis simulations, magnetic fluid analyses, quantitative assessments, identification assessments, etc., by fully utilizing our analytical know-how accumulated in the development and manufacturing of analysis instruments. Also, the Rigaku X-ray analysis instruments equipped with our magnetic fluid seals have been widely used around the world and have earned the trust of our customers.


Thorough quality control

Rigaku’s magnetic fluid seals have been advanced in line with the history of semiconductors. In the semiconductor industry requiring the utmost levels of cleanliness, the same level is also required for seal parts. We don’t think that magnetic fluid seals are just the parts. We provide our products after conducting thorough pre-process cleaning of parts, post-process cleaning and other processes to eliminate causes of contamination.

Responding to new needs

Rigaku’s magnetic fluid seals have been conventionally used as a rotary seal mainly for semiconductor manufacturing equipment, FPD manufacturing equipment, solar cell manufacturing equipment and other devices in the field of high-tech industries.
Because of the advantages of minimal torque loss and the capability of high-speed rotation as well as the excellent properties in “cleanliness”, “high vacuum / high pressure resistance” and “long service life”, various industries have been paying attention to our products as a seal suitable for any kind of application.

Product Information

Standard Products

Custom-made (Special-order) Products

Repairment / Overhaul


List of frequently asked questions about our products.



Download from here for drawings / product catalogues / instruction manuals.

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