AN Weld Bung 4AN Male Aluminum

The AN Weld Bung 4AN Male Aluminum is a precision fluid-system component designed for high-performance engine builds, custom fuel systems, and hydraulic line modifications. Whether you're fabricating a custom fuel rail, installing an aftermarket cooling system, or building a race-ready power plant, this aluminum weld bung serves as a sealed port terminator and adapter point. Mechanics and fabricators rely on these bungs to cap unused AN fittings during system pressure testing and to provide clean, leak-free connection points where off-the-shelf components don't fit. The 4AN size accommodates standard -4 hose or tubing assemblies, making it a staple in any serious automotive workshop.

Constructed from aluminum alloy, this weld bung features a male AN thread profile that interfaces directly with female AN ports, tees, and manifold inlets. The aluminum construction delivers a lightweight solution ideal for weight-conscious builds while maintaining corrosion resistance in fuel and coolant environments. The weld flange design allows technicians to TIG or MIG weld the component directly into custom-fabricated manifolds, tanks, or frame-mounted brackets, creating permanent, pressure-rated connections. Unlike compression fittings that rely on mechanical sealing, the welded bung approach eliminates potential leak paths and provides superior reliability at elevated pressures typical in turbocharged and supercharged engine systems.

This component is essential for custom fuel system builders, race engine fabricators, and hot rod enthusiasts who demand precision and reliability. Common applications include mounting fuel pressure regulators, installing turbo drain lines, sealing unused manifold ports, and adapting legacy carburetor systems to modern EFI setups. The 4AN male threading accommodates standard AN hose fittings and adapters found across the automotive aftermarket, ensuring broad compatibility with fuel injection systems, intercooler piping, and coolant bypass circuits. Installation requires welding equipment and basic metal fabrication knowledge; proper heat control prevents aluminum warping and maintains AN thread integrity.