Tweco 1240-1221 Mig Welding Nozzle 5/8 Inch Bore 450A

Product Description

The TWECO 1240-1221 is a heavy duty short stop copper MIG welding nozzle designed for use with Tweco No. 4 MIG guns rated up to 450 amps. The nozzle housing is cut and formed from 122 DHP copper alloy tubing, giving it the thermal conductivity needed for sustained high-amperage work. With a 5/8 inch (0.625 inch) bore diameter and an overall length of 3.48 inches, it maintains a recessed contact tip relationship of 0.125 to 0.156 inches. This recess geometry suits applications requiring longer electrical stick-out or situations where the nozzle may contact the workpiece. Sold as a pack of 2.

This nozzle is intended for medium to heavy duty MIG welding applications up to 450 amps. The recessed tip design makes it well suited for higher heat environments where extended electrical stick-out improves arc control and reduces spatter buildup at the nozzle face. It slides over the standard nozzle insulator, part number 34A (stock number 1340-1100), and is compatible with Tweco No. 4 standard gas diffuser configurations. Welding professionals working on structural, fabrication, or industrial maintenance applications will find this nozzle a direct fit for their existing No. 4 gun setup.

Key Features

• 122 DHP copper alloy construction for high thermal conductivity and durability in sustained high-amperage welding
• 5/8 inch bore with 0.97 inch OD accommodates heavy shielding gas flow at up to 450 amps
• Recessed contact tip relationship of 0.125 to 0.156 inches reduces spatter adherence and suits longer stick-out applications
• Part number roll-stamped on the exterior surface for fast field identification
• Slides over standard nozzle insulator part 34A (stock number 1340-1100) for straightforward installation
• Sold as 2 per pack

Compatibility

Designed for use with Tweco No. 4 MIG guns with standard gas diffuser configurations rated up to 450 amps. Mounts over standard nozzle insulator part number 34A (stock number 1340-1100).

Installation Notes

Installation should be performed by a qualified welding technician with the MIG gun fully de-energized and the wire feeder disabled before handling nozzle components. Ensure the nozzle insulator is clean and undamaged before sliding the nozzle into position. Inspect the nozzle bore for spatter buildup regularly, as excessive accumulation can restrict shielding gas coverage and degrade weld quality. Follow all applicable AWS and shop safety guidelines when servicing MIG gun consumables.

Technical Specifications

• Bore Diameter: 0.625 inches
• Nozzle Length: 3.48 inches
• Outside Diameter: 0.97 inches
• Maximum Amperage: 450 amps
• Recessed Tip Relationship: 0.125 to 0.156 inches
• Material: 122 DHP copper alloy
• Package Weight: 0.33 pounds
• Package Width: 1.1 inches
• Package Height: 1.1 inches
• Package Length: 3.4 inches
• Sold As: 2 per pack

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1240-1221