Tweco 1040-1138 Mig Gun 400A 15 Ft Air Cooled

Product Description

The TWECO 1040-1138 is a Professional No. 4 Classic Series air-cooled MIG gun rated at 400 amps with a 15-foot lead cable and Miller-style rear connection. Designed for semi-automatic MIG welding, it accepts 5/64-inch wire and delivers a 60% duty cycle when running CO2 shielding gas. The three-layer conductor tube construction — copper tube, silicon-resin glass insulator, and metal jacket — provides a reliable current path from handle to contact tip. A fully insulated Mig-Kwik connection at the wire feeder end allows fast connection and disconnection without tools. The 60-degree metal jacket conductor tube swivels 360 degrees around the handle, making repositioning quick during continuous production runs. Licensed welders and fabrication shop technicians are the primary installers and users of this gun.

This gun is suited for medium- and heavy-duty fabrication environments including production welding, maintenance and repair, farm and shop work, and artistic metalworking. The oval-shaped handle is balanced to pivot at its center, reducing grip fatigue during extended use. A steel spring strain relief at the rear of the handle supports the Cablehoz and minimizes wire feed problems. A gun hanger at the bottom of the handle allows the operator to rest the gun safely between passes. Two ball-point screws lock the Cablehoz and conductor tube securely in place, and the split-half handle case allows field repair without additional connectors.

Key Features

• 400-amp rating with 60% duty cycle on CO2 shielding gas
• Accepts 5/64-inch wire diameter with heavy-duty contact tip
• 360-degree swivel, 60-degree metal jacket conductor tube for flexible positioning
• Silver-plated trigger contacts with self-cleaning action on every actuation
• Fully insulated Mig-Kwik connector for tool-free connection and disconnection at the wire feeder
• Three-layer conductor tube construction for durability in high-heat applications
• Field-repairable split-half handle; front-end consumables interchangeable with Tweco Spray Master series

Compatibility

Features a Miller-style rear connection for use with compatible Miller wire feeders. Front-end consumables are interchangeable with the Tweco Spray Master series and other Tweco Professional No. series guns.

Installation Notes

Installation and service should be performed by a qualified welding technician or trained fabrication professional. Disconnect and de-energize the welding power source and wire feeder before connecting or servicing the gun. Ensure the Mig-Kwik connection is fully seated and locked before resuming operation. Follow the wire feeder manufacturer's guidelines and applicable ANSI/AWS safety standards when setting up or changing consumables.

Technical Specifications

• Amperage: 400 amps
• Duty Cycle: 60% with CO2 gas
• Wire Size: 5/64 inches
• Lead Length: 15 feet
• Conductor Tube Angle: 60 degrees
• Conductor Tube Swivel: 360 degrees
• Cooling Method: Air cooled
• Connection Style: Miller style rear connection
• Package Dimensions: 23.1 inches x 14.5 inches x 3.3 inches
• Weight: 11.75 pounds

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1040-1138