Abstract: A wire feeder with an integrated adaptor cartridge is provided. The adaptor cartridge comprises a cartridge body interchangeably mounted to the wire feeder for mechanical, welding current, and control signal connections. The adaptor cartridge further comprises an adaptor fitting for establishing the mechanical and welding current connections, and a control signal connector for establishing the control signal connection. The adaptor cartridge is preferably recessed within a housing of the wire feeder to protect the adaptor cartridge. A set of such adaptor cartridges is also provided for providing mechanical, welding current, and control signal connections for a respective one of the welding apparatuses to the wire feeder. Therefore, a single wire feeder can work with a set of welding apparatuses by selecting a suitable adaptor cartridge from the set of adaptor cartridges.