1. IN A VACUUM RELAY, AN EVACUATED ENVELOPE INCLUDING A DIELECTRIC BULB HAVING A CYLINDRICAL WALL PORTION, MEANS DEFINING AN END WALL SEALED TO ONE END OF SAID BULB, SAID END WALL HAVING AN OPENING THEREIN COAXIAL WITH THE AXIS OF SAID CYLINDRICAL WALL PORTION, A BELLOWS HERMETICALLY SEALED AT ONE END THEREOF TO THE OUTER SURFACE OF SAID END WALL ABOUT SAID OPENING, SAID BELLOWS BEING POSITIONED OUTWARDLY OF SAID WALL, A CIRCULAR MAGNETIC PLATE SEALED TO AND CLOSING THE OPPOSITE END OF SAID BELLOWS, A RIGID FIXED CONTACT MOUNTED IN SAID BULB, A MOVABLE CONTACT MOUNTED IN SAID BULB FOR MOVEMENT INTO AND OUT OF ENGAGEMENT WITH SAID FIXED CONTACT, AN ACTUATOR ROD OPERATIVELY CONNECTING SAID MOVABLE CONTACT TO SAID MAGNETIC PLATE, MAGNETIC MEANS MOUNTED ON SAID END WALL FOR MOVING SAID MAGNETIC PLATE INCLUDING A CORE MOUNTED ADJACENT SAID MAGNETIC PLATE, AND ADAPTED UPON ENERGIZATION TO MOVE SAID PLATE OUTWARDLY, A COIL SURROUNDING SAID CORE FOR ENERGIZING SAID CORE, AND A HOUSING OF MAGNETIC MATERIAL SURROUNDING SAID CORE AND COIL.