10401931 - Tweco Classic 4 MIG Gun 400A 12ft Lincoln Connection 1/16 Wire

Heavy-Duty Industrial MIG Gun

The Tweco Classic No. 4 (SKU: 10401931) is a premier air-cooled semi-automatic MIG gun designed for high-amperage welding applications. Renowned for its durability and performance, this model is rated at 400 Amps at a 60% duty cycle when using CO2 shielding gas, making it suitable for structural steel fabrication, heavy equipment manufacturing, and general industrial welding. The gun features a 12-foot cable assembly, providing a balance of reach and wire feedability.

This specific configuration is engineered with a Lincoln-style rear connection, allowing for seamless integration with Lincoln Electric wire feeders without the need for adapters. It comes factory-setup to run 1/16-inch (1.6 mm) welding wire, ideal for heavy-deposition flux-cored or solid wire applications. The Classic No. 4 utilizes the widely standardized Tweco consumable platform, including 14 Series contact tips, 24 Series gas nozzles, and 54 Series gas diffusers. This ensures that replacement parts are readily available and cost-effective.

The construction of the Classic No. 4 emphasizes longevity and ease of repair. It features a heavy-duty metal-jacketed conductor tube and a rugged handle that resists impact and heat. The cable assembly is designed to resist kinking and abrasion, protecting the internal copper stranding and liner. Maintenance personnel appreciate the mechanical cable connections, which allow for field repairs without specialized crimping tools.

Technical Specifications

The gun operates on a standard air-cooling mechanism, eliminating the complexity of water coolers while maintaining high thermal capacity. The trigger is designed for a long life cycle, and the overall ergonomics reduce operator fatigue during extended welding shifts. Whether used for GMAW (MIG) or FCAW (Flux-Cored) processes, the Tweco Classic No. 4 delivers consistent arc stability and reliable wire feeding.