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NACHI Ball Screw Support Bearings have been improved to exceed new industrial demands for high precision and high requirements. NACHI TAB type ball crew support bearings support precision actuators in wide range of applications such as machine tools, precision measuring equipment, and robot technologies.

High Axial Rigidity
Greatrer number of balls with polyamide cage achieves significantly increased rigidity compared with conventional angular contract ball bearing.
Simple and Compact
The 60º contact angle allows the bearing to simultaneously carry the thrust load and certain amount of radial load. This characteristic allow you to have a simple and compact design.
High Capacity and Low Noise
The use of large balls results in higher bearing capacity beyond what NACHI adopted with the poly-amide cage combined with the high performance, quiet operating, grease to achieve low noise.
Energy Saving
Superior seal designs offer low starting and running torque;
minimizing power loss.
Easy Assembly
Initial bearing preloading provides for ease of assembly by eliminating complex assembly adjustment.


  • With angular contact ball bearings, the balls and the inner ring and outer ring raceways from a specific angel of contact. When used in a single Configuration, axial load is limited to a Single direction, this type of bearing is suitable for bearing composite loads made up of axial and radial loads.
  • Since this type of bearing has a contact angle, axial components are generated when a radial load is applied. Because of this, this type of bearing is normally used in pairs at either end of a shaft.
  • Ceramic ball type also available.
Contact Angle
Two Angles are available : 15º and 25º. 15º is for high-speed applications. 25º is for applications requiring high axial rigidity.
A ball guide polyamide cage is provided as standard. The polymide cage should be used under temperatures lower than 120º.
Dimensional Accuracy, Rotational Accuracy
Conforms to JIS Class 5 or Class 4.
  • Four types of standard preload settings are available. Use the nearby table to select the preload that meets your criteria.
  • See page 16 throuht 18 for standard preloads available for each series and size.



  • Smaller machine steel balls, higher speeds, and lower temperatures than preveous angular contact ball bearings. Mainly used for the main sprindle of high-speed machining centers.
  • Ceramic ball type also available.
Contact Angle
15º contact angle provided as standard.
Outer ring guided phenolic resin cage provided as standard. Ball guided polymide resin cage also available.
Dimensional Accuracy, Rotational Accuracy
JIS Class 4 compliance as standard. 




  • Comparatively simple construction provides high accuracy. A large number of rollers for high rigidity.
  • Fewer sliding sections than a tapered rollar bearing so less heat is generated.
  • This bearing cannot bear axial load, so normally it is used in combination with a thrust bearing.
Both the NN3000 Series and NNU4900 Series are provided with brass alloy roller guide cage as standard.
Dimensional Accuracy, Rotational Accuracy
  • Conforms to JIS Class 5 or Class 4. 
  • Nachi defines its own tolerance values for accuracy of dimesions.
Radial Internal Clearance
Nachi defines its own non-interchangeable clearance for cylindrical bores and tapered bores in order to minimize axial run-out inconsistency.


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