14390 - Miller B-Size Regulator to A-Size Fuel Hose Adaptor (Left-Hand Thread)

Connect Light-Duty Hoses to Standard Regulators with Ease

Don't let mismatched fittings stop your project in its tracks. The Miller 14390 Adaptor is the perfect solution for welders and fabricators who need to connect an A-size fuel hose to a standard B-size regulator. Often, light-duty torches and hoses—common in HVAC, plumbing, and detailed metal art—come with smaller "A" fittings (3/8"-24). However, most standard industrial gas regulators are equipped with larger "B" outlets (5/8"-18). This high-quality brass adaptor bridges that gap instantly, allowing you to hook up your specialized gear to standard shop tanks without swapping out the entire regulator.

Built by Miller Electric, a name synonymous with durability in the welding industry, this adaptor is designed to withstand the rigors of daily shop use. The solid brass construction ensures that threads won't strip easily and that the fitting resists cracking even under wrench pressure. Because it is designed for fuel gases like Acetylene and Propane, it features Left-Hand threads (indicated by the notch on the nut in many fittings, though this is a solid adaptor piece). This safety feature prevents accidental cross-connection with oxygen lines, keeping your shop safe from dangerous mix-ups.

Installation is straightforward. Simply thread the female end of the adaptor onto your regulator's outlet and tighten it down. Then, screw your A-size hose nut onto the male end of the adaptor. The precision machining ensures a snug, leak-free fit, so you don't waste gas or risk safety hazards. Whether you are a professional contractor needing versatility on the job site or a hobbyist working with a specific torch setup, this adaptor is a must-have in your toolbox.

Stop searching for hard-to-find hoses or expensive specialty regulators. With the Miller 14390, you get the flexibility to use the right torch and hose for the job, powered by the equipment you already own. It’s a small part that makes a big difference in shop versatility and efficiency.