These pulleys spin freely on built-in bearings to maintain tension for reduced wear and vibration. They’re often used with belt tensioners(soldseparately).
Steel and castiron pulleys are more durable than nylon pulleys.
Pulleys with ballbearings ensure proper positioning inside a tube or housing. They’re sealed to block out dust and contaminants better than pulleys with needle roller bearings.
Pulleys with needlerollerbearings minimize internal friction.
For technical drawings and 3-D models, click on a part number.