A backshell encloses the area where wires are soldered or crimped to the pins of a circular or D-subminiature connector. It provides strain relief, shields against electromagnetic interference, and seals the joint against moisture and dust. They range from simple plastic clamps to heavy machined metal housings with environmental seals.
Make sure you slide the backshell onto the cable before you start crimping the pins.
Forgetting to put the backshell over the wire bundle before terminating the pins is a classic rookie mistake that requires cutting everything off and starting over.
Related terms
Connector
An electromechanical device used to join electrical terminations and create an electrical circuit.
D-sub
A family of electrical connectors featuring a distinctive D-shaped metal shield around multiple pins.
Crimp
To mechanically deform a metal connector around a wire to create a secure electrical connection.