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Sapphire to Metal for Fluidic,Metrology&Medical Components

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Ruby Ball

The AFBMA (Anti-Friction Bearing Manufacturers Association) sets standards for the manufacturing of precision balls, including sapphire balls and half balls. Sapphire balls are made from sapphire material, which is a type of crystalline form of aluminum oxide. They are often used in precision applications that require high wear resistance, such as bearings, valves, and flow meters.

Here are the standard sizes for sapphire balls and half balls as per AFBMA:

Sapphire&Ruby Balls:



  • Size range: 0.4mm to 63.5mm
  • Tolerance grades: ABMA Grade 3 through 1000 (Grade 3 being the most precise)
  • Surface finish: Ra 0.025 to 0.20 microns
  • Size range: 1.0mm to 12.7mm
  • Tolerance grades: ABMA Grade 3 through 1000 (Grade 3 being the most precise)
  • Surface finish: Ra 0.025 to 0.20 microns



Sapphire&Ruby  Half Balls:

Note that these are just the standard sizes and tolerances as per AFBMA, and there may be variations or custom options available from individual manufacturers.


Each ball is checked 100% for size accuracy and polish before delivery. The maximum precision we can achieve is ABMA Grade 3. Customized packaging options are available according to customer needs."


For more information or other materials and requests, please contact us.