Durability

Durability

* The standard connectors were designed to be robust. Many previous connector designs were fragile, specifying embedded component pins or other delicate parts which proved vulnerable to bending or breakage, even with the application of modest force. The electrical contacts in a USB connector are protected by an adjacent plastic tongue, and the entire connecting assembly is usually protected by an enclosing metal sheath. Although meant to reinforce the metal connections, the construction and materials used in the plastic tongue can actually decrease the life of the connector, as some manufacturers use hard, brittle plastics that easily break when bent.[citation needed]
* The connector construction always ensures that the external sheath on the plug makes contact with its counterpart in the receptacle before any of the four connectors within make electrical contact. The external metallic sheath is typically connected to system ground, thus dissipa