Smoother than smooth—the balls inside roll nearly friction-free to support smooth rotation. They mount securely in thin panels.

All bearings come lubricated. Plan to relubricate regularly to keep them in tip-top shape. Seals and shields hold lubricant in while keeping dust and contaminants out. Open bearings require more frequent relubrication.

Leave the lubricant in the supply closet—these low-maintenance sleeve bearings are made from naturally slippery plastic. They'll keep shafts spinning with no messy grease to drip off, wash out, or collect dust. With no moving parts, sleeve bearings withstand grimy environments better than ball bearings. However, with more friction generated, they're less effective at high speeds. They mount securely in thin panels.