of the particular die halves 03 04 the flat rail 14 extends over the entire length of crimping die 01 but has a smaller width than center piece 13 of the two die halves 03 04 by this means between rail 14 and cuboid shaped center piece 13 a step 16 is formed which forms a guide for insertion of crimping die 01 into crimping pliers 02 the lateral surfaces of open jaw like locking element 08 make possible lateral guidance during insertion of crimping die 01 into crimping pliers 02 guidance can also be attained by other structural measures such as a through running opening into which one or more pins of the pliers engage insertion direction 12 is perpendicular to closing direction 06 so that the configuration of die 01 as regards the crimping function is for the most part independent of its configuration as regards the insertion function by this means for example it is ensured that the locking connection is not broken by pressing force when the pliers are being closed at their ends the flat rails 14 are angled off so that a hook 17 is formed the hooks 17 are located at the end of rail 14 facing outwards which is directed away from insertion direction 12 thus they are located at the periphery of crimping pliers 02 vis u00e0 vis crimping pliers 02 the hooks 17 have no function in the position shown in fig1 the pliers 02 are in a position that.