Hardened Carbon Steel Ball Bearings Bearing Balls φ30.163mm-200mm High Precision

Measure the inner diameter of your bearing race or the seat bore using a micrometer or digital caliper. The ball diameter should match the original specification exactly. If replacing a ball in an existing bearing, refer to the bearing manufacturer's datasheet or measure a worn ball with a micrometer. Many imperial sizes are included in this listing — for example, φ31.75mm = 1-1/4 in, φ38.1mm = 1-1/2 in, φ50.8mm = 2 in, φ63.5mm = 2-1/2 in, and φ76.2mm = 3 in.

These balls are through-hardened carbon steel with a surface hardness typically in the range of 60–66 HRC. Higher hardness means the ball resists deformation under compressive load, which is essential for maintaining dimensional accuracy and extending service life in bearing and valve applications. Softer balls would deform over time, increasing play and causing noise or failure.

Carbon steel bearing balls are not inherently corrosion-resistant. In wet, humid, or outdoor environments, they should be used with appropriate lubrication (grease or oil) and ideally housed in a sealed bearing to prevent moisture contact. For applications requiring corrosion resistance, stainless steel bearing balls would be a more suitable choice. Contact us to confirm if you need an alternative material.

These balls are manufactured to G10–G40 grade depending on the diameter. Smaller diameters typically achieve tighter tolerances (G10–G16), while larger diameters are graded G25–G40. G-grade refers to the ABMA/ISO ball grade standard, where a lower number indicates tighter roundness and diameter variation tolerances. For most replacement and industrial applications, G25–G40 is fully adequate.

Yes, provided you select the correct ball diameter that matches the original bearing specification. Standard deep groove ball bearings use balls of a defined diameter determined by the bearing series and bore size. Always verify the ball diameter from the bearing manufacturer's datasheet before ordering. These balls are also suitable for angular contact bearings, thrust bearings, and custom assemblies where the ball diameter is specified.

Each order unit is priced and fulfilled as one (1) ball. If you need multiple balls — for example, to replace a full complement in a bearing — simply set the quantity accordingly at checkout. For bulk orders of 10 or more balls of the same size, contact us for volume pricing options.

Yes. Hardened carbon steel balls are widely used as valve balls in check valves, ball valves, and hydraulic circuits where a hard, dimensionally accurate ball is required to seat against a valve seat and create a reliable seal. Ensure the ball diameter matches the valve seat specification. For high-pressure hydraulic applications, verify the pressure rating with your valve manufacturer.