Trans Line Adapter 1/8in -27 NPT X 5/16in 2 Pack

The Northern Radiator Trans Line Adapter 1/8in -27 NPT X 5/16in 2 Pack is a precision fluid transfer fitting engineered to bridge two different port standards in cooling systems, fuel systems, and hydraulic applications. This straight adapter pair connects 1/8 inch NPT (National Pipe Thread) male ports to 5/16 inch SAE flare male connections, enabling reliable flow between components with mismatched thread specifications. Manufactured from brass, these adapters deliver corrosion resistance and long-term durability in high-temperature and pressurized environments.

The brass construction resists oxidation and maintains structural integrity across thermal cycling, a critical factor in radiator systems and transmission cooler installations where temperature fluctuations are constant. The 1/8in NPT thread standard provides excellent sealing characteristics when wrapped with appropriate thread sealant, while the 5/16in SAE flare connection ensures a positive mechanical seal without relying on tapered threads alone. The straight configuration—as opposed to angled fittings—simplifies installation in confined spaces and reduces stress on adjacent tubing. Each adapter in this 2-pack carries consistent tolerances, essential for applications where leakage could compromise system performance or damage surrounding components.

These adapters serve automotive builders, hot rod enthusiasts, and system technicians standardizing non-matching port configurations. Common applications include custom radiator plumbing, transmission cooler line adapters, and aftermarket heating or cooling circuit modifications. The 2-pack quantity addresses typical dual-circuit repairs or installations where redundant fittings ensure continuity of service. Proper installation requires compatible female SAE flare fittings on the 5/16in side and NPT-compatible ports or swaged fittings on the 1/8in side.