304 Stainless Steel Ball Bearings — Precision-Ground Solid Balls from 1mm to 90mm
When a loose or corroded ball causes a bearing assembly to seize mid-project, the cost is more than just downtime. DIYers, machinists, and maintenance professionals who work with linear slides, drawer runners, check valves, or custom jigs need replacement balls they can trust to be round, smooth, and corrosion-resistant from day one. These 304 stainless steel ball bearings deliver exactly that — available in 69 diameters spanning 1mm to 90mm (0.039 in to 3.54 in), sold individually or in bulk packs of up to 500.
Each ball is machined from A2-grade 304 stainless steel, a chromium-nickel alloy that resists rust, oxidation, and mild chemical exposure. Diameters range from 1mm (≈0.039 in) up to 90mm (≈3.54 in), with both metric and fractional imperial sizes included (e.g., 2.381mm / 3/32 in, 3.175mm / 1/8 in, 6.35mm / 1/4 in, 12.7mm / 1/2 in, 25.4mm / 1 in, 31.75mm / 1-1/4 in, 38.1mm / 1-1/2 in, 50.8mm / 2 in, 63.5mm / 2-1/2 in, 76.2mm / 3 in). Pack quantities of 1, 5, 15, 50, 200, and 500 are available depending on diameter.
Typical applications include replacing worn balls in drawer slides and cabinet hardware, loading check valves and ball-type flow controls, filling custom ball-transfer units for conveyor or workbench use, and serving as precision spacers or load-distribution elements in fabricated fixtures. The smooth surface finish and consistent sphericity make these balls suitable for both functional mechanical use and decorative or craft applications where a polished stainless look is required.
⚙️ Compatibility note: These are loose solid balls — not pre-assembled bearing units. Verify the bore diameter of your housing or race before ordering. Fractional imperial equivalents are listed in the variant selector for cross-reference.
✅ Key Features of These 304 Stainless Steel Ball Bearings
🔩 A2 / 304 Stainless Steel
Chromium-nickel alloy construction resists rust, oxidation, and mild acids — suitable for damp environments, outdoor fixtures, and food-adjacent applications.
📏 69 Diameters: 1mm – 90mm
Covers metric sizes from 1mm to 90mm and includes common fractional imperial equivalents (1/8 in, 1/4 in, 1/2 in, 1 in, 2 in, 3 in), reducing the need to source from multiple suppliers.
🎯 Precision-Ground Spherical Surface
Consistent sphericity and smooth surface finish allow these balls to seat correctly in races, valves, and transfer units without causing premature wear on mating surfaces.
📦 Flexible Pack Quantities
Order as few as 1 ball for a one-off repair or up to 500 for production restocking. Pack options (1, 5, 15, 50, 200, 500) scale to both workshop and light industrial needs.
🔄 Broad Application Range
Suited for drawer slides, check valves, ball-transfer units, conveyor systems, custom jigs, decorative hardware, and any assembly requiring a free-rolling or load-bearing sphere.
⚖️ Metric & Imperial Sizes in One Listing
Fractional imperial sizes (3/32 in through 3 in) are stocked alongside standard metric diameters, making cross-referencing straightforward for mixed-standard workshops.
📐 Technical Specifications — Stainless Steel Ball Bearings
| Material |
304 (A2) Stainless Steel |
| Diameter Range |
1mm – 90mm (0.039 in – 3.54 in) |
| Available Diameters |
See variant options (69 sizes) |
| Pack Quantities |
1 / 5 / 15 / 50 / 200 / 500 (availability varies by diameter) |
| Surface Finish |
Precision-ground, smooth spherical |
| Corrosion Resistance |
Rust and oxidation resistant; suitable for damp and mildly corrosive environments |
| Ball Type |
Solid (not hollow) |
| Imperial Equivalents Included |
Yes — fractional sizes from 3/32 in to 3 in |
| Weight (per ball) |
See variant options |
❓ Frequently Asked Questions
How do I choose the right diameter for my application?
Measure the inner diameter of the race, housing, or valve seat the ball must fit. For drawer slides and cabinet hardware, the ball diameter is typically stamped on the slide body or listed in the manufacturer's spec sheet. If you are replacing an existing ball, measure it with calipers before ordering. Fractional imperial equivalents are listed in the variant selector for cross-reference with inch-based specifications.
Are these balls suitable for use in check valves or flow-control applications?
Yes. 304 stainless steel is commonly used in check valves handling water, light oils, and mild chemical solutions. Confirm that the fluid in your system is compatible with 304 SS before installation. For highly corrosive media (e.g., chlorinated solutions or strong acids), 316 stainless steel may be more appropriate — contact us to confirm suitability.
What is the difference between A2 stainless steel and standard carbon steel balls?
A2 (304) stainless steel contains approximately 18% chromium and 8% nickel, which forms a passive oxide layer that resists rust and oxidation. Carbon steel balls are harder and less expensive but will corrode when exposed to moisture without protective coatings. Choose stainless when the application involves humidity, water contact, or food-adjacent environments; choose carbon steel when maximum hardness and load capacity are the priority in a dry environment.
Can I use these balls in a ball-transfer unit or conveyor system?
Yes. Loose stainless steel balls are a standard component in ball-transfer units. Select the diameter that matches the socket bore of your transfer unit housing. For conveyor applications, verify the load rating of the transfer unit itself — the ball material contributes to corrosion resistance but the unit's housing determines the load capacity.
Are these balls precision-grade, and what surface finish can I expect?
These balls are precision-ground with a smooth spherical surface suitable for mechanical and functional use in slides, valves, and transfer units. They are not certified to a specific ABEC or ISO grade. If your application requires a documented grade tolerance (e.g., G10, G25, G100), contact us to confirm before ordering.
Why are some diameters only available in smaller pack quantities?
Larger diameter balls (typically above 22mm) are heavier and less commonly ordered in bulk, so pack options are limited to smaller quantities for those sizes. Smaller diameters (1mm–22mm) are available in packs up to 500. The variant selector will show which pack sizes are available for your chosen diameter.
Are fractional imperial sizes (e.g., 1/4 in, 1/2 in) included in this listing?
Yes. Common fractional imperial sizes are stocked alongside metric diameters. Examples include 2.381mm (3/32 in), 3.175mm (1/8 in), 6.35mm (1/4 in), 12.7mm (1/2 in), 25.4mm (1 in), 31.75mm (1-1/4 in), 38.1mm (1-1/2 in), 50.8mm (2 in), 63.5mm (2-1/2 in), and 76.2mm (3 in). These are listed by their metric equivalent in the variant selector.
🛒 Select your diameter and pack quantity above, then add to cart.
