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When a loose fit or undersized ball causes vibration, noise, or premature wear in your bearing assembly, the fix starts with sourcing the right diameter. Machinists, engineers, hobbyists, and maintenance technicians who need a specific ball size — not just a standard — will find this listing covers 245+ incremental diameters from 2.3 mm to 9.605 mm, stepping as fine as 0.002 mm between sizes.
Each ball is machined from stainless steel (grade typically 304 or 440C equivalent) and supplied in packs of 100. Diameters span 2.3 mm (approx. 0.091 in) through 9.605 mm (approx. 0.378 in), with intermediate steps covering common metric, fractional-metric, and near-inch equivalents such as 3.175 mm (1/8 in), 6.35 mm (1/4 in), and 7.938 mm (5/16 in).
Typical applications include replacement balls for radial and angular-contact bearing races, precision valve seats requiring a stainless steel ball check, lapping and grinding fixtures where a known-diameter reference ball is needed, and DIY linear-motion or robotics builds where off-the-shelf bearing sizes do not match the housing bore.
From 2.3 mm to 9.605 mm with steps as fine as 0.002 mm — find the exact size your assembly requires without custom machining.
Corrosion-resistant alloy withstands moisture, mild chemicals, and outdoor exposure, extending service life in demanding environments.
Uniform roundness and surface finish support low-friction rolling and reduce noise in bearing races and valve seats.
Each variant ships as a pack of 100 same-diameter balls — enough for batch replacement, prototyping, or stocking a workshop supply.
Includes sizes matching 1/8 in (3.175 mm), 3/16 in (4.763 mm), 1/4 in (6.35 mm), and 5/16 in (7.938 mm) for cross-reference with inch-standard housings.
Select the diameter that matches your worn or missing balls for a direct replacement without modifying the housing or race.
| Material | Stainless steel (corrosion-resistant alloy) |
|---|---|
| Diameter Range | 2.3 mm – 9.605 mm (approx. 0.091 in – 0.378 in) |
| Diameter Increment | As fine as 0.002 mm between adjacent sizes |
| Number of Size Options | 245+ variants |
| Pack Quantity | 100 balls per pack |
| Surface Finish | See variant options |
| Grade / Tolerance | See variant options |
| Weight (per pack) | See variant options |
| Common Fractional Equivalents | 3.175 mm (1/8 in), 4.763 mm (3/16 in), 6.35 mm (1/4 in), 7.938 mm (5/16 in) |
| Typical Applications | Bearing race replacement, valve seats, lapping fixtures, robotics, DIY linear motion |
Measure the diameter of the existing balls with a micrometer or digital caliper. Match that measurement to the closest available size in this listing. If you are replacing a full set, measure several balls and use the most common reading. For valve seats, measure the seat bore and select a ball diameter that provides the correct interference or clearance fit per your design spec.
Stainless steel balls offer good hardness and compressive strength suitable for light-to-medium radial and axial loads in standard bearing assemblies. For heavy-load or high-speed industrial bearings, verify the grade matches your application's dynamic load rating. These balls are well-suited for replacement, prototyping, and moderate-duty use.
Stainless steel provides inherent corrosion resistance against moisture, humidity, and mild chemical exposure. They are suitable for outdoor equipment, marine-adjacent environments, and applications where occasional water contact occurs. For highly aggressive chemical environments, confirm compatibility with the specific alloy grade before use.
Yes. The listing includes sizes that correspond to common inch-standard ball diameters expressed in metric: 3.175 mm = 1/8 in, 4.763 mm ≈ 3/16 in, 6.35 mm = 1/4 in, and 7.938 mm = 5/16 in. Select the diameter that matches your housing specification. Always verify with a caliper before ordering if tolerance is critical.
Many adjacent sizes in this listing differ by only 0.002 mm. This level of precision matters when replacing balls in a precision bearing race where the original diameter must be matched closely to maintain the correct internal clearance. For less critical applications such as decorative or low-load uses, a size within ±0.05 mm is typically acceptable.
If your application uses a non-standard or worn-to-size diameter that does not match common catalog sizes, this listing is the right choice because it covers fine increments not found in standard kits. If your housing accepts a common size (e.g., exactly 1/4 in or 6 mm), a standard kit may offer a lower per-ball cost. Use this listing when precision diameter matching is the priority.
Yes. Every diameter variant in this listing is sold as a pack of 100 balls of that single diameter. There is no mixed-size pack option. Select the specific diameter you need from the variant selector above.
