Abstract: A subassembly for microwave structure such as a connector is described. An insulator for spacing of at least one center conductor is formed of PTFE (polytetrafluoroethylene) and effectively bonded to at least one center conductor to be used in the connector. The PTFE may be bonded to the conductor by employing an intermediate layer of FEP (fluorinated ethylene-propylene) that can be bonded to the center conductor. Bonding of the components into an integral subassembly is done in a single step involving heating and pressurizing a pre-assembly in a mold to a sufficient amount and for a sufficient time to provide an acceptably strong bond. Superior electrical characteristics such as a low SWR and insertion loss are achieved in captivated and/or sealed connectors. A good seal is achieved between the insulator and the outer conductor by forming an undercut in the latter, filling it with silicone grease and enabling a temporarily mechanically-collapsed bead on the insulator to expand into the undercut.