8-4015 - Tweco 4A-90 Conductor Tube 90 Degree Torch Head

Tweco 8-4015 4A-90 Conductor Tube Overview

The Tweco 8-4015 (Model 4A-90) is a premium replacement conductor tube designed for heavy-duty industrial MIG welding applications. Engineered to fit the widely used Tweco Spray Master 450 and the classic No. 4 series MIG guns, this component serves as the critical structural and electrical link between the gun cable and the consumables. The '90' in the model designation indicates a standard 90-degree bend, providing the ergonomic angle preferred by operators for general fabrication and bench work.

Manufactured from high-grade copper alloy, the 4A-90 ensures maximum electrical conductivity and efficient heat dissipation, which is essential when operating at amperages up to 450A. The assembly features a robust outer jacket that provides electrical insulation and protection against impact, spatter, and radiant heat. This main body assembly is precision-machined to accept standard Tweco diffusers and nozzle insulators, ensuring a gas-tight seal and stable arc performance.

Replacing a damaged or clogged conductor tube is vital for maintaining weld quality. Over time, internal buildup or physical deformation can restrict wire feeding and gas coverage. The Tweco 8-4015 offers a direct OEM fit, ensuring that maintenance personnel can restore the welding gun to factory specifications without modification. It is compatible with standard Tweco consumables, making it a versatile stock item for shops utilizing Tweco air-cooled MIG systems.