Are steel balls considered metal parts?

The Metallic Genes of Steel Balls
Steel balls are, of course, metal components! They are precision-machined from steel, essentially miniature metal spheres. Common materials include bearing steel and stainless steel alloys, which give them wear-resistant and pressure-resistant properties. Despite their small size, they rotate tens of thousands of times per minute in bearings without deforming, thanks to the rigidity of the metal.

The Versatile Little Ball of Industry
This small sphere plays a vital role in the mechanical field:

Transmission systems: As a core component of bearings, it reduces friction.

Crushing equipment: Thousands of steel balls act as "iron fists" in ore crushers.

Precision measurement: High-precision steel balls are used to calibrate the flatness of instruments.

Everyday items: Even the tip of a ballpoint pen contains a miniature steel ball.

Alternatives for Non-metallic Balls
When special needs arise, ceramic or plastic balls also come into play:

Electronic devices requiring insulation.

Strong acid and alkali environments.

Weight-sensitive applications.