10401922 - Tweco Classic 4 MIG Gun, 400A, 15ft, Miller Style

Industrial Grade 400A MIG Welding Gun

The Tweco Classic No. 4 MIG Gun (SKU: 1040-1922) represents the industry standard for heavy-duty air-cooled GMAW applications. Rated at 400 Amps at a 60% duty cycle using CO2 gas (300 Amps with mixed gas), this gun is engineered for high-deposition welding in structural steel, heavy equipment manufacturing, and general fabrication environments. The unit features a 15-foot cable assembly terminated with a Miller-style rear connection, ensuring seamless integration with compatible Miller wire feeders and power sources without the need for adapters.

Technically, the Classic No. 4 is built around a robust coaxial cable design known as Cablehoz®. This assembly combines the power conductor, gas hose, and control leads into a single, durable unit protected by an abrasion-resistant outer jacket. The conductor tube is metal-jacketed and insulated, providing a 60-degree bend for optimal access to weld joints while maintaining superior thermal and electrical conductivity. The gun utilizes the widely available Tweco 14 Series contact tips, 24 Series gas nozzles, and 54 Series gas diffusers, simplifying inventory management for consumables. The mechanical trigger switch is designed for high-cycle reliability, minimizing downtime associated with switch failure.

Maintenance and serviceability are core tenets of the Classic No. 4 design. The gun is fully field-repairable, allowing technicians to replace liners, trigger switches, conductor tubes, and cable assemblies individually. The connection pin is precision-machined to ensure positive electrical contact and stable gas flow, reducing voltage drop and porosity risks. This specific configuration (VM415116) comes factory-setup for standard wire diameters, typically ranging from 0.035" to 0.045", but can accommodate up to 5/64" wire with the appropriate liner and contact tip changes.