Super Precision Angular Contact Ball Bearings


ACBB, thrust, ROBUST, Polyamide-Cage, 2Comp

NSK offers a wide lineup of super precision angular contact ball bearings to provide optimal specifications for your application.

Our bearings provide the perfect solution for equipment requiring high running accuracy or high rotational speed, such as the main spindles of machine tools.


Lineup Highlights

  • Standard bearings that conform to ISO standards and specialized series for machine tools
  • Sealed bearings with prepacked grease
  • A range of NSKROBUST™ high-performance bearings for both high rigidity and ultra-high speeds

Product List

NSK's standard super precision angular contact ball bearings conform to ISO standards.


  • Long-life materials
    NSK's Z steel, a long-life bearing steel, is used as standard material.
  • Seals for even longer life
    Series 70 and 79 offer over 1.5x longer grease life than that of open bearings thanks to the included seals.
  • Cage options
    Two types of cages are available to suit your application.
NSKROBUST™ Ultra-High-Speed Angular Contact Ball Bearings

NSKROBUST bearings were developed using NSK’s flagship material, evaluation, and analysis technologies and offer especially high performance in machine tools. Sealed options allow for even longer life, improving machine tool reliability.

These features reduce impacts on the environment and help to save energy.


  • High speeds
    The NSKROBUST Series reduces heat generation and achieves high-speed rotation.
  • Long life
    X-type bearings feature heat- and wear-resistant SHX steel for long life in high-speed applications.
  • Wide lineup
    A variety of contact angles and ball materials meet needs across applications.
  • Sealed options for even longer life
    A wide range of sealed types offer 1.7x longer grease life than that of open bearings.
NSKROBUST Spinshot™ II Ultra-High-Speed Angular Contact Ball Bearings with Oil-Air Lubrication

Spinshot II bearings further optimize lubrication to achieve remarkably quiet operation with ultra-high-speed rotation.


  • Oil-air lubrication realizes extremely high speeds
    Spinshot II bearings support speeds up to 40,000 min-1 using oil-air lubrication with NT#40 tooling.
  • Quiet operation
    Noise levels reduced by 3-5 dB compared to conventional oil-air lubrication.
NSKROBUST™ BSR Series Ultra-High-Precision Angular Contact Ball Bearings

The BSR Series provides high precision and ultra-high speeds for shaft diameters of 25 mm or less. This high-performance line is designed to support compact machine tool spindles.


  • Ultra-high speeds
    BSR Series bearings are specialized to meet the ultra-high speeds required by small machine tool spindles.
  • Long life
    X-type bearings feature heat- and wear-resistant SHX steel for long life in high-speed applications.
  • High precision
    High-precision specifications come standard.
NSKROBUST™ High-Speed Angular Contact Thrust Ball Bearings

NSKROBUST angular contact ball bearings sustain axial loads under high speeds and with high rigidity.


  • High rigidity/low heat generation
    The BTR Series features a contact angle of 40° for both high thrust rigidity and low heat generation.
  • High speeds
    The BAR Series features a contact angle of 30° for a boost in high-speed performance.
TAC-F Series Highly Rigid Angular Contact Thrust Ball Bearings

TAC-F Series angular contact ball bearings are designed to receive axial loads with a particular focus on rigidity.


  • High rigidity
    A contact angle of 50° is used to enhance rigidity, perfect for highly rigid spindles operating under heavy-duty cutting applications.
  • User friendly
    An inseparable design makes these bearings easy-to-handle.



answersThe various series have internal designs specialized for certain applications.
Generally, we recommend our Standard Series for precision machinery, the NSKROBUST Series for ultra-high speeds, the BSR Series for small shaft diameters, and the TAC Series for high-rigidity when receiving thrust (axial) loads.


answersWe recommend filling 15 to 30% of the bearing's free internal space with grease.
If too much grease is used, abnormal heat generation will occur when the machine starts, causing the grease to deteriorate.


Industry Applications