What Is a Bearing Ball?

Bearing balls are spherical components often employed as rolling mechanisms within rotary motion devices, such as bearings, tooling, and wheels. Within these devices, they reduce the rotational friction between components and support radial and/or axial loads. Other common use cases include employment as media in grinding or burnishing operation or components in toys. They are available in several different materials to suit the requirements and restrictions of various applications.



Bearing Ball Materials

Industry professionals use bearing balls made from a variety of materials, the choice of which depends on the intended application. Some of the most common bearing ball materials include:


  • Aluminum. Aluminum balls exhibit good corrosion and wear resistance and smooth surface finishes, qualities that make them suitable for high-friction applications. They are often used in bearings and valves, automotive, electric, and welding safety devices, and aerospace and aviation equipment and systems.


  • Brass/copper/bronze. These materials are non-magnetic and electrically conductive. The latter of which makes balls made from them suitable for use in electrical and electronic applications. They are also employed in various plumbing and valve applications.


  • Ceramic. Ceramic bearing material comes in many variations, ranging from ruby ball to aluminum oxide ball material. It is highly resistant to corrosion and thermal damage, as well as accommodates minimal lubrication and acidic/alkaline environments.


  • Glass. Glass bearing balls demonstrate excellent corrosion resistance, good mechanical properties, and electrical insulation properties. As they are available in varying degrees of transparency, they are suitable for use in optical applications.


  • Plastic. Plastic bearing balls have low material density and high corrosion resistance. Depending on the application, they can be made from different formulations with enhanced performance properties, such as abrasion resistance or temperature resistance.


  • Stainless steel. Both hardened stainless steel and non-hardened stainless steel are used in the manufacture of bearing balls. Hardened variations offer greater toughness and wear resistance, making them suitable for use in industrial bearings. Non-hardened stainless steel is more workable but has less corrosion resistance. Balls made from it are commonly employed in electronic devices.


  • Steel and other steel alloys. Bearing balls can be made from a variety of steel alloys, such as bearing steel, carbon steel, and tool steel. The performance characteristics they demonstrate vary based on the construction material chosen.


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Applications of Bearing Balls

Bearing balls see regular use in a wide range of applications as a component that separates and reduces the friction between moving parts. They are employed in parts and products ranging from industrial devices and equipment to games and toys. Other applications include:

  • Components in optical equipment and systems
  • Elements in art and decorative pieces
  • Large-scale cladding in buildings
  • Media in surface finishing applications, such as blasting, burnishing, grinding, peening, polishing, and dent removal


Bearing Balls From STR Industries

For any customer that uses bearing balls, the choice of where to get bearing balls is critical. Partnering with an experienced supplier ensures they receive quality components that meet their needs.

At STR Industries, we have more than five decades of experience manufacturing steel balls, which gives us the expertise needed to deliver high-precision, high-accuracy bearing balls suitable for use in a wide range of applications. Our products are available in many different grades, sizes, and materials to suit different customer needs:


  • Grades (as per AMBA): 3, 5, 10, 16, 24, 48, 100, 200, 1000
  • Sizes: varies based on grade (see our steel balls page for the sizing chart)
  • Materials: aluminum, bearing steel, brass, bronze, carbon steel, ceramic, copper, glass, plastic, stainless steel, tool steel


Available Grades and Sizes:

Grade Size Range (inches)
3 025" - 3/16"
5 .025" - 1 1/2"
10 1/32" - 2 1/2"
16 1/32" - 2 1/2"
24 1/32" - 2 1/2"
48 1/32" - 2 1/2"
100 1/32" - 4 1/2"
200 1/32" - 4 1/2"
1000 1/32" - 4 1/2"


Our TS 16949 certification demonstrates our commitment to quality management and continuous improvement, emphasizing defect prevention in design, development, and production with an added commitment to the reduction of waste in all aspects of production. We offer inspection on 100% of our products. Our pricing is very competitive - on average, our customers save 20-30% on manufacturing costs.


For additional information about our bearing ball offerings or a quote on pricing, contact us today.