CAFRA SCHLÜSSEL are dovetailing or connecting units that function by means of friction due to material expansion. The CAFRA SCHLÜSSEL series 100, 200, 300, 400, 500 and 600 are used to block mechanical members like pulleys, toothed wheels, gears, pinions and all types of hubs on shafts, ensuring the power transmission between the two members involved. They are dovetailers that allow to carry out axial adjustments between shaft and hub thus avoiding fixed blocking systems. The catalogue shows 40 application examples that explicate the numerous advantages these dovetailers may offer. The CAFRA SCHLÜSSEL series 700, 800, 900 and 1000 can be used as connection units for plates and square, rectangular or round tubes. Furthermore they allow one to compound steel structures such as bedplates, protections or crankcases for machines with profiles and to dismount them again at any moment. The catalogue presents 20 application examples that describe the ease with which one can rigidly connect tubes of any shape or plates, without any welding.