Tweco 1140-1209 Mig Contact Tip 0.078 in 400A 25 Pack

Product Description

The TWECO 1140-1209 is a heavy-duty MIG contact tip designed for high-amperage semiautomatic welding applications up to 400 amps. Built from extruded or gun-drilled 122 DHP copper alloy and machined from copper alloy tubing, it delivers consistent electrical conductivity and a smooth inside diameter surface held to a tolerance of plus or minus 0.003 inches. The tip measures 1.47 inches in length with a 0.09-inch nominal bore, a 0.283-inch OD, and a 1/4-28 UNF-2A thread. It accommodates 5/64-inch (0.078-inch) wire and is sold in packs of 25. Licensed welding technicians and MIG welding professionals rely on this tip for sustained heavy-duty production welding cycles.

This contact tip is intended for use with Tweco No. 2, No. 3, and No. 4 MIG guns rated from 200 to 400 amps, as well as compatible specific MIG gun series. It fits both slip-on and thread-on nozzle styles. The tip locks in place with a quarter-turn clockwise twist, which also allows the operator to rotate the tip when the initial wear point is reached, exposing a new wear point and effectively doubling tip service life. Its thick-walled construction acts as a heat sink, drawing heat away from the arc source during extended welding operations.

Key Features

• Accommodates 5/64-inch (0.078-inch) MIG wire with 0.09-inch nominal bore
• 122 DHP copper alloy construction machined to plus or minus 0.003-inch ID tolerance for consistent wire feed
• Quarter-turn twist-lock design secures tip to gas diffuser and increases electrical contact surface area
• Rotatable wear-point design doubles usable tip life without replacing the tip immediately
• Thick-walled heat-sink design conducts heat away from the arc source during high-amperage use
• Part number and wire diameter marked directly on tip for fast identification during changeouts
• Rated for heavy-duty welding up to 400 amps

Compatibility

Designed for use with Tweco No. 2, No. 3, and No. 4 MIG guns rated 200 to 400 amps. Compatible with both slip-on and thread-on nozzle styles. Thread size is 1/4-28 UNF-2A.

Installation Notes

Installation is performed by qualified welding technicians. Power down and de-energize the MIG gun completely before replacing contact tips. Thread the tip hand-tight into the gas diffuser and verify the twist-lock engages before resuming welding. Inspect the diffuser threads for wear or spatter buildup before installing a new tip to ensure proper seating and electrical contact.

Technical Specifications

• Wire Diameter: 0.078 inches (5/64 inch)
• Bore (Nominal ID): 0.09 inches
• Outside Diameter: 0.283 inches
• Length: 1.47 inches
• Thread Size: 1/4-28 UNF-2A
• Maximum Amperage: 400 amps
• ID Tolerance: plus or minus 0.003 inches
• Material: 122 DHP copper alloy
• Package Quantity: 25 per pack
• Weight: 0.02 pounds (per unit)

Standard Information

• Brand: TWECO
• Manufacturer Part Number: 1140-1209