684 Bearing - Miniature Ball Bearing 4mm x 9mm x 2.5mm

684 miniature open ball bearing for high speed applications
✔️ 684 deep groove miniature bearing 4x9x2.5 mm

This single 684 miniature ball bearing is an open, deep groove design made from 52100 chrome steel. It’s commonly used in high speed devices, small motors, instruments, and precision builds where compact size and smooth rotation are key.

✅ Inner diameter: 4 mm
✅ Outer diameter: 9 mm
✅ Width: 2.5 mm
✅ Open design
✅ Material: 52100 chrome steel
✅ Standard precision grade
✅ Handles radial load with light axial load capability
✅ Pack size: one bearing

Dimensions
ID: 4 mm
OD: 9 mm
Width: 2.5 mm

💡 What makes miniature deep groove ball bearings suitable for high speed rotating systems?
Miniature deep groove bearings are designed to keep friction low while staying stable at speed.

• Deep raceways support smooth rolling under continuous rotation

• Compact geometry reduces centrifugal effects at higher RPM

• Chrome steel construction maintains hardness and shape over time

Use this bearing when you need clean, fast rotation in a tight space without added complexity.