Tweco 1240-1230 Mig Nozzle 3/4 Inch Bore 450A Heavy Duty

Product Description

The TWECO 1240-1230 is an adjustable copper MIG welding nozzle designed for use with Tweco No. 4 MIG guns rated up to 450 amps. Machined from 122 DHP copper alloy tubing, the nozzle measures 3.42 inches in length with a 3/4-inch bore and a 0.97-inch outer diameter. The contact tip-to-nozzle recess relationship is adjustable, allowing the installer to run the tip recessed, flush, or protruding depending on joint geometry and application. The part number is rolled-stamped on the outer surface for fast field identification. Sold in a pack of 2. This nozzle is intended for medium to heavy-duty welding applications and is installed by professional welders and fabricators.

This nozzle fits standard gas diffusers used with Tweco No. 4 MIG guns and is suited for medium to heavy-duty MIG welding environments operating up to 450 amps. The adjustable tip relationship makes it versatile across multiple joint types: recessed tip positioning works for high-heat applications and longer electrical stick-out; flush positioning suits shorter arc lengths and tighter stick-out; and protruding positioning allows access to open root pipe welds and tight joints where torch geometry is critical.

Key Features

• Adjustable contact tip relationship: recessed, flush, or protruding positions available
• Constructed from 122 DHP copper alloy tubing for excellent conductivity and heat resistance
• 3/4-inch bore with 0.97-inch OD — suited for medium to heavy-duty amperage work up to 450A
• Part number rolled-stamped on the outer surface for easy identification in the field
• Slides over standard nozzle insulator Part No. 34A (Stock No. 1340-1100)
• Sold as a 2-pack per unit

Compatibility

Designed for use with Tweco No. 4 MIG guns rated up to 450 amps and compatible with the standard gas diffuser and nozzle insulator Part No. 34A (Stock No. 1340-1100).

Installation Notes

Installation is performed by qualified welders or MIG gun technicians. Before replacing the nozzle, power down the welder and allow all components to cool fully. Thread or slide the nozzle over the gas diffuser and insulator assembly, confirming the tip position — recessed, flush, or protruding — matches the intended weld joint requirement before resuming operation. Inspect the nozzle and diffuser for spatter buildup regularly to maintain proper gas coverage and weld quality.

Technical Specifications

• Bore Size: 3/4 inch
• Outer Diameter: 0.97 inches
• Nozzle Length: 3.42 inches
• Maximum Amperage: 450A
• Material: 122 DHP Copper Alloy
• Contact Tip Relationship: Adjustable (recessed, flush, or protruding)
• Compatible Insulator: Part No. 34A (Stock No. 1340-1100)
• Weight: 0.33 pounds
• Quantity per Pack: 2

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1240-1230