Featuring a multi-step sleeve design, ConCentra ball bearing units are built to provide a secure and concentric fit. As special mounting screws are tightened during installation, the bearing unit’s inner ring is driven up a series of inclined planes to compress a sleeve around the shaft. For removal, the mounting screws are loosened and the dismounting screws and tightened to reverse the process. As a result, the bearings don’t have to be cut from shafting during removal. These ball bearings, which form close to a 360 degree interference fit with the shaft, are ideally suited for high-speed air handling applications. The units are said to reduce noise, vibration, and potential fretting corrosion; minimize risks of uneven load distribution, imbalance, and shaft damage; and enable units to run at their bearing’s full dynamic load capacity. The bearing unit’s concentric mounting technology works to ensure a high locking force without requiring extremely close shaft tolerances. For example, shaft tolerances of ISO h9/IT5 can be used. Shafts can be specified as commercial-grade or hollow, rather than ground, specially machined, or polished shafts often mandated with set-screw air-handling units. The units feature deep-groove ball bearings, which are either pre-lubricated for the life of the bearing (with special air-handling quality grease) or equipped with lubrication fittings. Their two-part sealing arrangement consists of a low-friction contact seal and phosphated metallic flinger to prevent intrusion of solid and liquid contaminants, enhance grease retention, and minimize maintenance demands.