1KG Solid 304 Stainless Steel Ball Precision Replacement Bearings 3mm - 20mm

Measure the diameter of the existing ball using a micrometer or digital caliper, or check the bearing race specification in your equipment's service manual. Match that measurement to the closest available size in the variant selector. For fractional-inch applications, use the metric equivalents listed: 3/16" = 4.763 mm, 1/4" = 6.35 mm, 5/16" = 7.938 mm, 3/8" = 9.525 mm, 1/2" = 12.7 mm.

304 stainless steel has a tensile strength of approximately 515 MPa and a hardness of around 70–90 HRB, which is adequate for light-to-medium duty applications such as drawer slides, casters, check valves, and small pneumatic actuators. For heavy-load bearing races or high-cycle industrial machinery, a hardened chrome steel or 440C stainless ball may be more appropriate. Contact us if you need to confirm suitability for a specific load rating.

304 stainless steel provides good resistance to rust and oxidation in fresh water, humid air, and mildly corrosive environments. It is not fully immune to corrosion in chloride-rich environments such as salt water or strong chemical exposure. For highly corrosive conditions, 316 stainless steel balls would offer better resistance. For typical indoor plumbing, food-adjacent equipment, or general workshop use, 304 performs reliably.

These balls are sized to standard metric and fractional-inch dimensions used in common bearing races, ball-check valves, and drawer-slide hardware. Compatibility depends on the specific seat or race diameter in your assembly. Always verify the required ball diameter against your equipment specification before ordering. If you are unsure, contact us with your application details and we can advise.

The quantity per pack varies by diameter because larger balls weigh more individually. As a general reference: a 1 kg pack of 3 mm balls contains significantly more pieces than a 1 kg pack of 20 mm balls. If you need an estimated piece count for a specific diameter, contact us and we can provide an approximate figure based on the density of 304 stainless steel (approx. 7.93 g/cm³).

304 stainless steel is widely used in food-processing equipment and is generally considered food-safe for incidental contact applications. However, if your application requires certified food-grade or medical-grade components with specific documentation (such as material certifications or FDA compliance letters), please contact us before ordering to confirm whether certification documents are available for this product.

Chrome steel (52100) bearing balls are harder (typically 60–65 HRC) and better suited for high-load, high-cycle precision bearing applications. 304 stainless steel balls are softer but offer superior corrosion resistance, making them the preferred choice when the operating environment involves moisture, mild chemicals, or where rust contamination is a concern. Choose stainless for corrosion resistance; choose chrome steel for maximum hardness and load capacity.