Tweco 1240-1877 Heavy Duty Mig Nozzle 5/8 Inch Bore

Product Description

The TWECO 1240-1877 is a heavy duty MIG welding nozzle from the Velocity2a series, designed for professional welders who demand reliable, consistent performance in demanding fabrication environments. Featuring a 5/8 inch bore, this nozzle uses a single-thread design that pairs brass threads on the nozzle body against heat-treated stainless steel threads on the gooseneck. The soft-against-hard thread combination resists seizing and cross-threading, a common failure point with standard MIG consumables. Licensed welding professionals and industrial fabricators install this nozzle as a direct consumable replacement during routine gun maintenance.

The 1240-1877 is suited for MIG welding applications in both production shop and field environments. The Velocity2a design eliminates the two or three thread sets found on conventional MIG consumables, reducing downtime during nozzle changes. The fixed threaded configuration maintains a consistent flush relationship between the nozzle opening and the contact tip, which supports repeatable weld positioning. This nozzle is sold individually and is appropriate for use in heavy duty MIG gun setups where bore size and thread reliability are critical to weld quality.

Key Features

• 5/8 inch bore size for heavy duty MIG welding applications
• Single-thread design reduces seizing, cross-threading, and tool dependency compared to conventional two- or three-thread consumables
• Brass nozzle threads mate against heat-treated stainless steel gooseneck threads for extended service life
• Fixed threaded style maintains consistent flushness between nozzle opening and contact tip
• Compact form factor at 2.25 inches in length for use in tight weld access situations

Compatibility

Designed as an OEM-style replacement nozzle for heavy duty MIG welding guns compatible with the TWECO Velocity2a consumable system.

Installation Notes

Installation is performed by qualified welders or maintenance technicians during routine MIG gun servicing. Disconnect and de-energize the welding power source before removing or installing any consumable components. The tool-free single-thread design allows hand installation without wrenches; do not use pipe wrenches or pliers on the nozzle body. Inspect the gooseneck threads for wear or spatter buildup before threading on a replacement nozzle.

Technical Specifications

• Bore Size: 5/8 inch
• Series: Velocity2a Heavy Duty
• Thread Design: Single-thread, brass on stainless steel
• Height: 2.25 inches
• Width: 1 inch
• Length: 1 inch
• Weight: 0.27 pounds
• UPC: 608246434681

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1240-1877