E99-320C44 - Miller Stainless Steel Inlet Nut, CGA 320 for CO2

Reliable CO2 Connections for Professional Welders

Keep your welding operations running smoothly with the Miller E99-320C44 Stainless Steel Nut. Designed specifically for CGA 320 connections, this nut is the essential link between your CO2 cylinder and your regulator. For MIG welders using straight CO2 for shielding—common in structural steel and heavy fabrication—having a reliable connection is key to consistent weld quality. A worn or stripped nut can lead to gas leaks, which not only wastes money but can also cause porosity in your welds due to inadequate shielding coverage. This genuine Miller replacement part ensures you get a tight, secure seal every time you swap out a tank.

Built from durable stainless steel, this nut is a significant upgrade over standard brass fittings. In a busy shop environment, equipment takes a beating. Threads can get crossed, and soft metals can deform after hundreds of tightening cycles. The stainless steel construction of the E99-320C44 offers superior hardness and strength, resisting wear and tear so you can rely on it for the long haul. It is also highly resistant to rust and corrosion, which is perfect if your rig is moved between indoor shops and outdoor job sites where moisture might be an issue. When you reach for your wrench, you want to know the nut will hold tight without stripping.

This part is designed to fit standard CGA 320 valves found on Carbon Dioxide cylinders. It is a direct replacement for the inlet nut on many Miller and Smith regulators. If you are refurbishing an older regulator or simply replacing a damaged part, sticking with OEM components is the best way to ensure safety and performance. Generic parts might look the same, but slight variations in thread quality can cause headaches down the line. With Miller, you know you are getting a part that fits perfectly and performs as expected.

Don't let a small part cause big downtime. Whether you are setting up a new beverage system, a hydroponic CO2 dosing system, or a heavy-duty MIG welding station, the Miller E99-320C44 is the professional's choice for a secure gas hookup. Pair it with the correct nipple and washer (if required for your specific setup) to ensure a leak-free system. Invest in quality fittings to protect your equipment and improve your process efficiency.