1. Basic characteristics of bearing balls
Material: GCr15 bearing steel (most common), ceramic (silicon nitride), stainless steel (440C/316)

Accuracy level: G3-G100 (ISO standard), the smaller the number, the higher the accuracy

Hardness: HRC 58-66 (steel)

Surface roughness: Ra ≤ 0.012 μ m (precision grade)

2. Main types
Ordinary steel ball: diameter tolerance ± 0.005mm

Precision steel ball: used for precision bearings, with a tolerance of ± 0.001mm

Ceramic ball: corrosion-resistant, insulated, and heat-resistant (800 ℃)

Stainless steel ball: specialized for food/medical machinery

3. Key manufacturing processes
Cold heading forming → Hard grinding processing → Heat treatment → Precision grinding → Ultra precision grinding

Ceramic balls need to be sintered and precisely ground after forming

4. Application Selection Guide
Ordinary machinery: GCr15 steel ball (economical type)

High speed spindle: G10 grade precision steel ball

Corrosion environment: 316 stainless steel or ceramic balls

Insulation requirement: Silicon nitride ceramic balls

5. Failure analysis
common problem:

Peeling: Overloading or fatigue failure

Wear and tear: caused by poor lubrication

Indentation: caused by impact load

Corrosion: Sealing failure or improper material

Suggestion:

When selecting, the PV value (pressure x velocity) should be considered

The curvature coefficient of the paired bearing channel should be matched

It is recommended to use ceramic balls (with low density) for high-speed applications