1. A METHOD OF PRODUCING COMMUTATORS COMPRISING THE STEPS OF UPSETTING THE MATERIAL OF ONE END OF A TUBULAR PART HAVING A LENGTH EXCEEDING THE FIAL LENGTH OF THE COMMUTATOR, IN ORDER TO FORM A FIRST INNER FLANGE ON SAID END OF SAID TUBULAR PART, SPLITTING OF THE OTHER END OF SAID SUBULAR PART IN AXIAL DIRECTION FOR A LENGTH WITHIN SAID EXCEEDING LENGTH OF SAID TUBULAR PART AND CONCENTRICALLY TO THE OUTER AND INNER SURFACES OF SAID TUBULAR PART, TO FORM AN INNER AND AN OUTER PORTION OF SAID OTHER END OF SAID TUBULAR PART, BENDING INWARDLY SAID INNER PORTION OF SAID OTHER END OF SAID TUBULAR PART TO FORM A SECOND INNER FLANGE, CUTTING LONGITUDIANL SLOTS INTO SAID TUBULAR PART SHORT OF SAID OUTER PORTION OF SAID TUBULAR PART, IN ORDER TO DIVIDE THE LATTER INCLUDING SAID FIRST AND SECOND FLANGES INTO A PLURALITY OF SEGMENTS AND TO REATIN AT FIRST SAID SEGMENTS IN POSITION BY MEANS OF SAID STILL INTEGRAL EXCEEDING LENGTH OF SAID TUBULAR PART, INSERTING INSULATING COMPOUND INSIDE OF AND INTO SAID LONGITUDINAL SLOTS IN RODER TO INSULATE SAID SEGMENTS FROM EACH OTHER AND TO EMBED SAID SEGMENTS IN SAID INSULATING COMPOUND, AND CUTTING OFF SAID STILL INTEGRAL OUTER PORTION OF SAID TUBULAR PART AND, THEREBY, SEPARATING NOW COMPLETELY SAID SEGMENTS FROM EACH OTHER.