639756 - ESAB ST-16/ST-21 MIG Gun Nozzle, 3/4 Inch Bore

Heavy-Duty Performance for Your ST-16 & ST-21 Guns

If you are running an ESAB ST-16 or ST-21 MIG gun, you know these torches are built for work. But even the toughest gear needs fresh consumables to keep laying down quality beads. The ESAB 639756 Nozzle (Size #12) is your go-to replacement when you need serious gas coverage. With a wide 3/4-inch bore, this nozzle is perfect for those high-heat jobs where a standard 1/2-inch nozzle just doesn't provide enough shielding. Whether you are welding thick structural steel or running hot spray transfer, this nozzle ensures your puddle stays protected from the atmosphere, helping you avoid porosity and rework.

We know that in the shop, durability counts. This nozzle is made from heavy-duty copper that stands up to the heat of long arcing times. It resists spatter adhesion better than cheaper aftermarket alternatives, meaning you spend less time banging your torch against the table and more time welding. The fit is precise, sliding securely onto your ST-series gun without wobbling, ensuring your gas flow is directed exactly where you need it.

Don't let a clogged or battered nozzle ruin your weld quality. A deformed nozzle can disrupt your gas flow, leading to erratic arcs and poor shielding. Swapping out your old nozzle for a fresh ESAB 639756 is one of the cheapest and easiest ways to instantly improve your weld consistency. Keep a few of these #12 nozzles in your kit so you are always ready for heavy fabrication tasks that demand the best coverage possible.