Abstract: An adjusting device for fastening a die to the clamping face of a press ram having a T-groove communicating with the clamping face, comprises a flexible but longitudinally non-stretchable traction member which is either movably mounted or fixed to the press ram and which extends in the T-groove. A tenon block is operatively connected to the traction member and carries an insert tightener. A drive motor drives the traction member so as to move the tenon block and its insert tightener in the T-groove so that the insert tightener can engage a clamping edge of a die or upper tool for holding the die or upper tool against the clamping face of the press ram.