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Engineers, hobbyists, and repair technicians who need reliable rolling elements know the frustration of sourcing the exact diameter — only to receive inconsistent roundness or surface finish that shortens service life. These GCR15 chrome steel ball bearings are stocked across a wide size range specifically to eliminate that sourcing gap, whether you are rebuilding a spindle, restoring a vintage mechanism, or prototyping a new device.
Each ball is manufactured from GCR15 bearing-grade chrome steel, a through-hardened alloy known for its uniform carbide structure and fatigue resistance. Diameters span 1 mm through 30 mm (approximately 0.039 in to 1.181 in), with many fractional-inch and metric increments available. Packing options are 10 pieces or 30 pieces per order.
Typical use cases include RC car and drone drivetrains requiring small-diameter precision balls (1 mm–6 mm), skateboard and inline-skate bearing replacement (6 mm–8 mm range), linear guide carriages and ball screws (8 mm–25 mm), and industrial machinery overhaul where exact replacement diameters are critical (up to 30 mm).
Through-hardened chrome steel alloy with uniform carbide distribution delivers consistent hardness (typically HRC 60–66) and extended rolling fatigue life across the full size range.
Available from 1 mm to 30 mm in metric and fractional-inch increments, covering the most common replacement and prototyping sizes in a single listing.
Ground and lapped to a tight spherical tolerance, these balls seat evenly in raceways and reduce vibration in high-speed or precision-load applications.
The chrome steel composition provides inherent resistance to mild oxidation during storage and normal indoor use. For wet or chemical environments, additional sealing or lubrication is recommended.
Choose 10-piece or 30-piece packs to match your project scale — from single-unit repairs to small-batch production runs — without over-ordering.
Suited for RC models, skateboards, linear motion systems, spindles, valves, and general mechanical assemblies where a precise rolling element is required.
| Material | GCR15 Chrome Bearing Steel |
|---|---|
| Diameter Range | 1 mm – 30 mm (0.039 in – 1.181 in) |
| Available Sizes | See variant options |
| Hardness (typical) | HRC 60–66 |
| Surface Finish | Ground and lapped spherical surface |
| Corrosion Resistance | Mild — suitable for dry/indoor use; lubrication recommended for wet environments |
| Packing Quantity | 10 pcs or 30 pcs per pack |
| Weight per Pack | See variant options |
| Application | Bearings, linear guides, ball screws, RC drivetrains, skateboards, machinery overhaul |
Measure the inner diameter of the raceway or the bore of the component the ball must fit. The ball diameter should match the specification on your bearing datasheet or the original part number. If replacing worn balls, measure an unworn ball with a micrometer for the most accurate reference. When in doubt, consult the bearing manufacturer's tolerance table for the grade required.
These balls are manufactured from GCR15 bearing-grade chrome steel and are ground to a tight spherical tolerance suitable for general-purpose and light-precision applications. For ultra-high-precision spindles requiring Grade 3 or Grade 5 balls per ISO 3290, please contact us to confirm the specific grade available for your required diameter.
GCR15 chrome steel provides moderate corrosion resistance for dry indoor use and short-term exposure to humidity. For outdoor, marine, or chemical environments, we recommend applying a compatible bearing grease or oil, or considering stainless steel balls instead. Prolonged exposure to water or corrosive media without lubrication will reduce service life.
Yes, provided the diameter matches the original ball specification exactly. When replacing balls in a sealed or shielded bearing, the bearing must be carefully disassembled, cleaned, and re-lubricated after ball replacement. This process requires precision tools and is typically performed by experienced technicians. Verify the ball count and diameter from the bearing's datasheet before ordering.
Both packs contain identical GCR15 chrome steel balls of the selected diameter. The 10-piece pack suits single-bearing repairs or small prototype builds, while the 30-piece pack offers a better per-unit value for batch production, stocking a spare set, or applications requiring multiple bearings of the same size.
Store unused balls in a dry, low-humidity environment away from direct contact with water or corrosive chemicals. Keeping them in the original sealed packaging or a clean, lidded container with a light coating of anti-rust oil will preserve the surface finish and prevent oxidation during long-term storage.
Yes. Several sizes in this listing correspond to common fractional-inch standards: 3.175 mm (1/8 in), 4.763 mm (3/16 in), 6.35 mm (1/4 in), 7.938 mm (5/16 in), 9.525 mm (3/8 in), 11.113 mm (7/16 in), 12.7 mm (1/2 in), 14.288 mm (9/16 in), 15.875 mm (5/8 in), 19.05 mm (3/4 in), 22.225 mm (7/8 in), and 25.4 mm (1 in). Select the size that matches your imperial specification.
