684 Full Ceramic ZrO2 Miniature Ball Bearings 4x9x4mm Pack of 30 High Precision Ceramic Bearings With PTFE Cage for Low Friction, Heat Resistance, Smooth Operation in Hobby, RC, Medical, and Industrial Projects

30-Pack Full Ceramic 4x9x4mm Mini Bearings
✔️ 30 bearings per pack; 4x9x4 mm, zirconia ceramic with PTFE cage

These 684 full ceramic miniature bearings use zirconia balls and zirconia races for exceptional hardness and corrosion resistance, delivering low friction in tight spaces. They’re ideal for precision micro assemblies in drones, RC models, 3D printers, and robotics.

✅ Bearing type: full ceramic (ZrO2) with PTFE cage
✅ Ball material: zirconia ceramic (ZrO2) for high hardness
✅ Races material: zirconia ceramic (ZrO2)
✅ Inner/outer dimensions: 4 mm ID, 9 mm OD, 4 mm width
✅ Cage material: PTFE
✅ Pack size: 30 bearings

💡 What is a ceramic miniature bearing used for in precision micro machinery? These bearings are handy in tight spaces where smooth motion and long life matter. - Handy in hobby robotics, micro motors, and 3D printers - Great in dusty or humid settings thanks to ceramic components - Delivers low friction and long wear life for compact machines - Works well with zirconia balls and PTFE cages for reliable motion