166571 - Miller Coolant Fitting - 3/8 Barb to 5/8-18 Female Adapter

Precise Connection for Liquid Cooling Systems

The Miller 166571 Fitting is a specialized component designed to facilitate the secure transfer of coolant within industrial welding setups. Engineered by Miller Electric, this fitting serves as a critical interface between flexible coolant lines and threaded connections on power sources, water coolers, or torch leads. It features a standard 5/8-inch - 18 female thread on one end, a common specification in North American welding equipment for gas and water connections, ensuring broad compatibility with Miller's extensive line of water-cooled TIG and MIG systems.

The opposing end utilizes a precision-machined barbed connection sized for 3/8-inch internal diameter (I.D.) tubing. This barbed design provides a robust mechanical grip on the hose, which, when secured with an appropriate clamp, creates a hermetic seal capable of withstanding the pressure and flow rates typical of recirculating cooling loops. Maintaining the integrity of these connections is paramount; even minor leaks can lead to coolant loss, reduced flow rates, and subsequent thermal damage to high-amperage torches and guns.

Constructed from durable materials, this fitting is built to resist corrosion and mechanical stress. In professional fabrication environments, equipment is often subjected to movement and vibration. Using genuine OEM parts like the 166571 ensures that the tolerances match the mating components perfectly, reducing the risk of cross-threading or seal failure. Whether you are repairing a damaged coolant line, retrofitting a new cooler, or performing routine maintenance on a TIG runner system, this fitting provides the reliability required for continuous industrial operation.

Technical specifications include a 5/8"-18 Female thread pitch and a 3/8" hose barb. Technicians should verify the thread direction and tubing size of their specific equipment before installation, as welding systems utilize various fittings for gas, water-in, and water-out lines. This part is supplied individually and is ready for immediate installation into your maintenance workflow.