D-sub backshells protect the rear termination area of a D-sub connector and provide the mechanical interface between the connector shell and cable. Depending on the design, a backshell can provide cable strain relief, shielding continuity, cable-exit control and mounting or mating hardware.
Wallco carries backshells and hardware for common D-sub shell sizes used with DB9, DB15, DB25, DB37, DB50 and related connectors. Materials range from molded plastic to metalized or metal hoods, with different cable clamp and screw arrangements.
Select a backshell by connector shell size, cable diameter, exit direction, shielding requirement and mating hardware. A hood that physically fits the connector can still be wrong if the cable clamp, screw thread or shielding method does not match the assembly.
Match the backshell to the connector shell size and contact count. Standard-density and high-density D-sub connectors can share similar external families while using different shell/contact arrangements, so use the connector specification as the reference.
Strain relief is a core backshell function because it reduces flexing and pull force at the solder or crimp termination. Check the supported cable diameter and clamp style before assembly.
Where EMI/RFI control matters, choose a shielded or conductive backshell and maintain a suitable cable-shield termination. TE Connectivity notes that backshells can provide strain relief, environmental protection and EMI/RFI shielding depending on the design.
Also verify jackscrews, thumbscrews and thread type. Mating hardware must match the equipment-side connector and provide enough engagement without bottoming out or leaving the connection unsecured.