NSK Develops Highly Corrosion Resistant, High Hardness, Stainless Steel ESZ Bearings

10 Times the Conventional Longevity Enables Use in Diverse Applications

Tokyo, Japan, March 24, 2010 - NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) announced today that it has developed highly corrosion resistant, high hardness, stainless steel ESZ bearings for use in corrosive environments. NSK will launch the new bearings in April 2010 and expects annual sales to reach 0.3 billion yen by 2011.

Highly Corrosion Resistant, High Hardness, Stainless Steel ESZ Bearings

NSK's SPACEA™ Series of bearings and linear guide products are specially designed for the needs of special environments, including vacuum, clean, corrosive and other demanding environments. NSK has now developed highly corrosion resistant, high hardness, stainless steel ESZ bearings suited to acidic, alkaline, and other corrosive environments and added them to the SPACEA™ Series.

The new bearings deliver a longer service life under acidic, alkaline, and other corrosive environments. They are ideal for use in supporting the rollers that transfer the high performance film used in solar panels and liquid crystal panels. The medium-size bearings use a cage made of polyether ether ketone (PEEK) resin, which provides excellent strength and corrosion resistance. These features will enable the new bearings to accommodate the development of the larger transfer rollers needed as solar panels and displays continue to grow in size.

The new bearings' outstanding corrosion resistance also makes them excellent for transport systems in fields related to food product machinery and medical devices for cleaning, disinfecting, and sterilizing.

Product features

Improved longevity through the use of new materials
The inner and outer races are made of the newly developed “highly corrosion resistant, high hardness stainless steel ESZ,” which boasts nearly 30% greater hardness than the conventional stainless steel product (SUS630). The rolling elements are made of ceramic balls that have excellent corrosion resistance and wear resistance. Use of these new materials enables a service life that is nearly 10 times greater than usual under corrosive environments, including underwater applications.
High corrosion resistance enables use even under corrosive environments
Use of the highly corrosion resistant,  high hardness, stainless steel ESZ bearings delivers ample durability under the acidic, alkaline, and other corrosive environments used in the cleaning process for high performance films. Moreover, the new bearings have excellent corrosion resistance to sodium hypochlorite solutions used for disinfecting and cleaning food product machinery and medical devices.
Suitable for a wide range of applications
Available in 26 sizes, varying from 10-60 mm in inside diameter and up to 110 mm in outside diameter, these bearings can meet diverse needs, ranging from the manufacturing process of high performance films for solar panels and liquid crystal TVs to the transport systems in fields related to food product machinery and medical devices.
Medium size bearings with an inner diameter of 35 mm or more, primarily for sustaining larger loads, come standard with cages made of PEEK resin, which provides high strength and high corrosion resistance. Smaller bearings, for applications such as the transport systems in fields related to food product machinery and medical devices, come with cages made out of a special fluororesin, which boasts not only high corrosion resistance but also the low friction needed to ensure lubricity.

NSK will continue to enhance its SPACEA™ Series bearings for special environments in order to meet diverse industrial needs in the future.