Abstract: The electrical connecting device comprises a male connector and a female connector, each provided with a casing and a contact-support body made of electrically insulating material, which can be coupled by means of threaded lock nuts. The contact-supporting body of the female connector, is made of elastomeric material and the female contacts of the connector are elastically yielding and press-fitted into appropriate seats of the contact-support body. The contact-support bodies of female and male connectors also comprise opposite annular sealing shoulder surfaces, designed to rest one against the other in the coupled condition of the two connectors.