KTR CLAMPEX-clamping elements, self-centering, shaft-hub connections. They allow for a backlash-free and non-positive connection between cylindric smooth shafts and hub bores without keyway. The clamping elements are clamped via integrated screws which are used for non-destructive untightening of the clamping elements in addition (KTR 150 series forms an exception). Depending on the type, the clamping elements are either untightened merely by declamping the screws or additionally pulling off the individual components of the clamping elements from each other. Among other things, CLAMPEX clamping elements are preferred as an alternative to feather key connections.