6mm Bore Bearing - 21mm Round Nylon Pulley U-Groove Track Roller 6x21x7mm

6mm Bore Nylon U-Groove Pulley with
✔️ Built-in Track Roller Bearing - 6x21x7mm

This is a single U-groove nylon pulley with a 6mm inner diameter and a built-in steel ball bearing. Commonly used in sliding doors, 3D printers, track systems, and automation setups where smooth guided motion is key.

✅ Size: 6mm x 21mm x 7mm
✅ Inner diameter (bore): 6mm
✅ Outer diameter: 21mm
✅ Tire width: 7mm
✅ Pulley material: White nylon
✅ Integrated steel ball bearing
✅ Style: U-groove round track
✅ Quantity: 1 bearing

💡 Why use a U-groove nylon pulley bearing for motion systems?
Because it reduces friction and enables smooth track-guided movement in tight, lightweight assemblies.
Perfect for motion control tracks, rail guides, or compact pulley systems
✅ Nylon material ensures low noise and wear resistance
✅ Steel bearing provides strength and durability
✅ U-groove profile allows smooth tracking on round rails

If you're building a track system or need reliable guided motion in tight spots, this pulley gets the job done - add one to your cart and keep your projects rolling!