KP2743-2-62S-B25 - Lincoln Magnum PRO 550A Slip-On Nozzle, 5/8 ID, 1/8 Stickout (25 Pack)

Technical Overview of the Lincoln Electric KP2743-2-62S-B25

The Lincoln Electric KP2743-2-62S-B25 is a high-performance gas nozzle designed specifically for the Magnum PRO series of semi-automatic MIG welding guns. Engineered to withstand the rigors of heavy industrial fabrication, this nozzle is rated for 550 Amps, making it suitable for high-deposition welding applications where thermal management is critical. The nozzle features a slip-on connection mechanism, which utilizes a friction fit over the gas diffuser. This design eliminates the threads found on traditional nozzles, preventing thread seizure caused by thermal expansion and spatter accumulation, thereby reducing downtime during consumable changeovers.

Dimensionally, the nozzle provides a 5/8-inch (15.9 mm) inner diameter (ID) or bore. This bore size is a standard configuration for medium to heavy-duty welding, offering a balanced shielding gas envelope that protects the weld pool from atmospheric contamination without inducing excessive turbulence. The specific geometry of this model includes a 1/8-inch (3.2 mm) contact tip stickout. This configuration means the contact tip protrudes slightly beyond the nozzle edge, which can enhance arc visibility and allow the welder to access tighter joints where a flush or recessed tip might be obstructed. The stickout geometry is particularly useful in short-circuit transfer modes or when welding in corners.

Supplied in a bulk package of 25 units, the KP2743-2-62S-B25 is intended for high-volume manufacturing environments. The use of high-grade copper alloy ensures excellent thermal conductivity, rapidly dissipating heat away from the front end of the gun to prolong the life of both the nozzle and the internal consumables. This product is a direct replacement for standard Magnum PRO 550A setups and integrates seamlessly with Lincoln Electric's proprietary expendable parts ecosystem.