8-5005 - Tweco 8-5005 Mounting Tube for No. 4 & 5 MIG Guns

Technical Overview: Tweco 8-5005 Mounting Tube

The Tweco 8-5005 (Stock No. 1850-0500) is a precision-machined brass mounting tube designed for the assembly and repair of Tweco No. 4 and No. 5 MIG guns. This component serves a vital mechanical role within the gun's handle assembly, providing the interface between the cable connection and the conductor tube (gooseneck). It is engineered to establish a rigid, non-conductive (when insulated properly) or conductive structural link depending on the specific gun architecture, ensuring the conductor tube maintains a fixed orientation relative to the handle.

Over time, the threads or the body of the mounting tube can suffer from mechanical fatigue, thread stripping, or heat cycling deformation. A compromised mounting tube can lead to a loose conductor tube, which results in poor electrical contact, increased resistance, and erratic arc performance. In severe cases, it can cause shielding gas leaks within the handle. The 8-5005 restores the gun to factory-new rigidity. It features precision-cut threads for a secure engagement with the cable adapter and the conductor tube locking mechanism.

Installation and Compatibility:

• Fitment: Specifically designed for the heavy-duty Tweco No. 4 (400 Amp) and No. 5 (500 Amp) air-cooled MIG guns.
• Material: High-grade brass alloy for corrosion resistance and mechanical strength.
• Function: Acts as the positioning skeleton inside the handle, preventing rotation of the neck during welding maneuvers.

For MRO professionals and welding technicians, keeping a stock of 8-5005 mounting tubes is recommended for fleets utilizing Tweco Classic series guns. Replacement is straightforward and requires disassembling the handle case. Ensure all O-rings and set screws are properly seated when installing this tube to maintain gas integrity and mechanical security.