A clamping bushing for removably securing two elements on each other, for example, a pulley on a shaft, so as to be exactly coaxial. The device consists of a tubular part which is slipped, for example, loosely over the shaft and has a pair of substantially radial flanges which extend at an angle of more or less than a right angle to the tubular part and have small coaxial tubular extensions on their outer ends which are fitted tightly, for example, into a cylindrical bore in a pulley. When a pressure is applied upon a pressure fluid in the chamber formed between the flanges, the tubular part and the wall of the bore, the flanges are bent to a more erect position and thereby increase in effective length so as to connect the two elements tightly to each other.