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Miniature & Instrument Series Ball Bearings
Ball Bearings

Miniature Bearings and Instrument Ball Bearings

AST Bearings has a huge selection of Miniature Bearings and Instrument Series Ball Bearings with over 500 types available. Precision tolerances from ABEC-1 through ABEC-9 are generally available for most miniature products. Typical bore sizes of miniature ball bearings start at 3 mm with an outside diameter a mere 10 mm. Custom-made miniature bearings can have bore sizes as small as 1 mm! 

Miniature & instrument series ball bearings

Bearings Catalog

Check out our online product catalog with more than 10,000 products with full specifications & 3D CAD Models available for download - all free of charge!

Many products are available in SV30 special stainless steel material (also in more common 400 and DD type Stainless Steel, 52100 Chrome Steel materials) in both inch and metric dimensions. Other major configurations from AST include:

  • Open miniature ball bearings
  • Open, with extended inner ring miniature ball bearings
  • Shielded miniature ball bearings
  • Shielded, with extended inner ring miniature ball bearings
  • Sealed miniature ball bearings
  • Sealed, with extended inner ring miniature ball bearings
  • Flanged, open miniature ball bearings
  • Flanged, open, with extended inner ring miniature ball bearings
  • Flanged, shielded miniature ball bearings
  • Flanged, shielded, with extended inner ring miniature ball bearings
  • Flanged, sealed miniature ball bearings
  • Flanged, sealed, with extended inner ring miniature ball bearings

Miniature Ball Bearings are small bearings with balls as their rolling elements.  These small bearings have an outside diameter of less than ?” (<9.525 mm) or are small bearings with an outside diameter less than or equal to ½” (≤ 12.7 mm) having a ration of outside diameter to inside diameter equal to or less than two.

AST Bearings specializes in miniature bearings (small bearings) of all kinds and is not limited to just miniature "ball bearings" as described above. Many times, the category of "miniature" is not defined with other types of bearings, they are simply smaller. If you are looking for other types of small bearings, you can find them elsewhere on our site in their respective categories including, but not limited to:

The term “Instrument Ball Bearing” is not limited to certain sizes, as with “miniature” ball bearings.  They are precision ball bearings with functional requirements which allow their use in the literal sense of the word.   The tolerances of instrument bearings are always ABEC-5 and higher.  Additionally, they must meet two or more of the following conditions: 

  • Low or uniform starting or running torque
  • Smooth operation or vibration limitations
  • A definite contact angle or preload (or both)
  • Meet high cleanliness standards

AST Bearings is proudly presenting our new certificates for both the NJ and CA locations: AST Bearings’ ISO 9001:2015 Certificates

To learn more about what the ISO 9001 standard is, the differences between the 2015 and 2008 versions, and how AST verifies customer satisfaction: Learn About AST Bearings’ certification to ISO 9001:2015

Need Assistance Selecting the Proper Miniature & Instrument Series Ball Bearings?

If you need help in selecting the best products for your particular application, please remember that design engineering and application assistance are available from AST as part of our value-added services designed to make your job easier.

Value added services

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