This adapter sleeve enables mounting of bearings with a tapered bore onto a cylindrical shaft seat, transmitting the clamping force generated by the locknut evenly around the bore diameter of 40.0 mm. The sleeve has a standard design and a net mass of 0.244 kg, providing a mechanical connection between the bearing bore and the shaft without requiring a machined shaft shoulder. The tapered fit created by the sleeve allows the bearing internal clearance to be set during mounting by controlling the axial drive-up distance, which is useful when the bearing must be positioned at any point along a smooth shaft. Since the sleeve is a separate accessory component, it must be paired with a matching locknut and, where applicable, a lock washer to secure the assembly and maintain the intended clamping force during operation.