Catalog Searcher
Categories

Ball

Balls are spherical components used as rolling elements in rolling bearings, ball screws and linear guides, where they carry loads while rolling. They are also used as valve bodies in check valves, reference spheres for positioning and measurement, grinding media for agitation, and tips for ballpoint pens. Materials include high-carbon chromium bearing steel (SUJ2), stainless steel (SUS440C and others), carbon steel, cemented carbide, ceramics such as silicon nitride, alumina and zirconia, non-ferrous metals, glass and resin. Dimensional accuracy is classified into grades defined by sphericity, diameter variation and other criteria; under JIS B 1501, a smaller grade number indicates higher accuracy. Material and grade are selected according to load, rotational speed, corrosion resistance, temperature, and magnetic or insulating properties required by the application.

How to choose Ball

  1. 1. Select the material to suit the application

    Bearing steel is used for high-load bearings, stainless steel where corrosion resistance is required, and carbon steel for light-load, low-cost applications. For high-speed bearings or vacuum environments that require light weight, non-magnetic properties or electrical insulation, silicon nitride is suitable; resin and glass are candidates for applications in contact with chemicals or where anti-rust oil cannot be used.

  2. 2. Determine the accuracy grade by required performance

    Grades are indicated as G3 to G1000 and others; a smaller number means smaller variation in sphericity and diameter. For low-noise, high-speed bearings such as machine tool spindles, select a smaller grade; for casters and light-load applications, select a larger grade to avoid over-specification.

  3. 3. Check nominal diameter and inch designations

    The nominal diameters of listed products range from 0.3 to 101.6 mm. Many inch-based nominal diameters are also available, such as 1/4 inch = 6.35 mm, so confirm whether the design values are metric or inch, and specify a size that matches the raceway groove and cage dimensions.

  4. 4. Evaluate rotational quality by sphericity and surface roughness

    Sphericity (2.5 to 25 μm for listed products) and surface roughness Ra (0.01 to 0.15 μm) directly affect vibration, noise and wear. When used as valve seals or reference spheres for measurement, confirm that these two values meet the required accuracy.

  5. 5. Check hardness and operating temperature

    Hardness relates to wear resistance and resistance to indentation, and is indicated in HRC or HV. For high-temperature use, check the maximum operating temperature (288 to 1000 °C for listed products) and hot hardness. Cemented carbide and ceramics tend to retain hardness at high temperatures.

  6. 6. Confirm whether secondary processing is possible

    Standard hardened steel balls are very hard, making drilling and welding difficult. For applications such as ball joints, where a shaft is welded to the ball or holes are drilled, select machinable products such as lightly carburized steel balls with shallower case depth, or cut balls with flat surfaces for retention.

This guide was written by AI based on the listed products' documents and specification items. Check each manufacturer's documents before adopting.