The Tweco Style 21 Series premium thread-on MIG gas nozzle boasts an innovative 3-piece design that eliminates the need for a separate insulator, streamlining assembly while delivering top-tier welding performance. Crafted for durability, the nozzle housing is expertly cut and formed from copper alloy tubing, paired with a solid brass alloy insert, ensuring long-lasting reliability in tough welding conditions. A built-in silicone insulator provides critical electrical insulation from the gas diffuser, enhancing both safety and efficiency, while the roll-stamped Part No. on the exterior allows for quick and easy identification. Available in 3/8", 1/2", 5/8", and 3/4" sizes, this nozzle supports light to medium-duty welding tasks up to 160 amperes, offering versatility for various applications. Compatible with Lincoln K530-5 100L Magnum, Tweco #1 100AMP MIG Gun, 160A Spool Guns, and others, it fits seamlessly with Tweco 51 Diffuser threads and 61 Series Tubes, making it an ideal choice for precision and convenience.