30 Pack Full Ceramic 638-2RS ZrO2 Miniature Ball Bearings 8x28x9mm High Performance Precision Bearings With PTFE Cage For Reduced Friction Long Lifespan And High Rigidity Suitable For Micro Motors Robotics Jewelry Making And Hobbies

30-Pack Full Ceramic 638-2RS Zirconia Bearings 8x28x9mm
✔️ 30-pack of full ceramic 638-2RS, 8x28x9mm, ZrO2 balls

These miniature bearings use zirconia ceramic balls and zirconia races with a PTFE cage, delivering low friction, corrosion resistance, and long life in precision machines, robotics, and high-speed gear systems.

✅ Inner diameter 8 mm, outer diameter 28 mm, width 9 mm
✅ Ball material: zirconia ceramic; races: zirconia ceramic
✅ Cage: PTFE; seal type: 2RS (rubber sealed)
✅ Pack size: 30 bearings per pack

💡 What is a ceramic ball bearing used for in precision machinery?

They’re handy in high-speed, clean environments where low friction and corrosion resistance matter.

- High-speed spindles and CNC equipment

- Medical and lab instruments with clean environments

- Aerospace and robotics requiring tight tolerances