An adapter sleeve is a mechanical component used to mount bearings with tapered bores onto cylindrical shafts. It is typically made of steel and consists of a cylindrical sleeve with a tapered bore on its inner surface and a corresponding tapered outer surface that matches the taper of the bearing's bore. The adapter sleeve is installed onto the shaft and tightened with a nut or bolt, which compresses the sleeve and creates a tight fit between the shaft and the sleeve. The bearing is then mounted onto the adapter sleeve, which provides a secure and precise fit for the bearing. Adapter sleeves are commonly used in industrial applications, such as conveyor systems, pumps, and fans, where it is important to have accurate alignment between the bearing and the shaft.