In a method for compression of the insulation in armature end windings, before hardening, multichamber, profiled pressure tubes (1) are introduced in the region of the end winding. They are inserted between the coils or winding bars (6). Application of defined internal pressure presses these against the sides of the formed coils or bars (6) over their full height. This presses together the individual layers of insulation (7). Following completion of the hardening process, the tubes are removed. Also claimed is the equipment to carry out the procedure, in which preferably the tubes comprise fabric-reinforced silicone rubber of controlled Shore hardness. A silicone gel filling is included. A polytetrafluoroethylene shell of similar characteristics may be used.