Tweco 1230-1120 Mig Nozzle 5/8 Inch Bore 450 Amp Thread-on

Product Description

The TWECO 1230-1120 is a 23 Series self-insulated, thread-on MIG welding nozzle rated for use with up to 450-amp Tweco No. 3 MIG guns. It features a 5/8-inch (0.625 inch) bore, a 0.875-inch outer diameter, and measures 3.219 inches in length. The nozzle strings directly into the conductor tube assembly. Construction is a 3-piece design: a nozzle housing cut and formed from 122 DHP copper alloy tubing, a nozzle insert machined from solid brass to match internal gas diffuser threads, and a G7 silicone nozzle insulator that provides the required electrical isolation from the gas diffuser. The part number is rolled-stamped on the outer surface for quick field identification. Sold as 2 per pack.

This nozzle is intended for heavy-duty MIG welding applications where output levels reach up to 450 amps. The recessed contact tip relationship of 0.125 to 0.156 inches makes it well suited for higher-heat passes, longer electrical stick-out requirements, tack welding, spot welding, stitch welding, and situations where the nozzle may contact the workpiece. The 9/16-inch-18 UNC-2B thread size ensures positive engagement with compatible conductor tube assemblies. It is used by professional welders and fabricators in industrial and heavy manufacturing environments.

Key Features

• 3-piece self-insulated design eliminates the need for a separate external insulator
• Nozzle housing formed from 122 DHP copper alloy tubing for high conductivity and heat resistance
• Nozzle insert machined from solid brass with internal threads matched to the gas diffuser
• G7 silicone nozzle insulator provides durable electrical isolation from the gas diffuser
• Recessed tip geometry supports longer stick-out, tack, spot, and stitch welding applications
• Part number rolled-stamped on outer surface for fast identification in the field
• Thread-on attachment with 9/16-inch-18 UNC-2B thread

Compatibility

Designed for use with Tweco No. 3 MIG guns rated up to 450 amps. The nozzle threads into the conductor tube assembly and the insert is machined to match gas diffuser thread specifications for that platform.

Installation Notes

Installation is performed by professional welders or maintenance technicians. Always power down the welding machine and allow front-end components to cool before removing or installing nozzle consumables. Thread the nozzle onto the conductor tube by hand until fully seated to avoid cross-threading the UNC-2B threads. Inspect the silicone insulator and brass insert for wear or heat damage at each consumable change to maintain proper electrical isolation and gas coverage.

Technical Specifications

• Bore Diameter: 0.625 inches
• Outer Diameter: 0.875 inches
• Nozzle Length: 3.219 inches
• Current Rating: 450 amps maximum
• Thread Size: 9/16 inches-18 UNC-2B
• Contact Tip Relationship (Recess): 0.125 to 0.156 inches
• Attachment Type: Thread-on
• Nozzle Housing Material: 122 DHP copper alloy
• Nozzle Insert Material: Solid brass
• Nozzle Insulator Material: G7 silicone
• Package Weight: 0.22 pounds
• Sold As: 2 per pack

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1230-1120