I figured buying a Lincoln accessory for the Lincoln MIG torch would provide a precise fit. I was wrong. The first half inch of the nozzle has smooth holes and is designed to go through the base of the gas diffuser and slide onto the end of the gun itself. Then the internal thread begins, which engages in the external thread at the base of the diffuser. The nozzle must clear the end of the gun before the threads can engage. With the nozzle I received, the smooth bore area was too small and I couldn't hook the filaments. I had to bore it out on a lathe to get it wide enough to work. For an imported part I would consider that tolerable, but not from the manufacturer.