6AN 3/8NPT Pipe Plug Hex Head Black 2/pkg

The 6AN 3/8NPT Pipe Plug Hex Head Black (2/pkg) is an essential hydraulic and fuel system component for serious engine builders, performance mechanics, and custom automotive enthusiasts. These compact adapter plugs seal off unused AN (JIC) port connections in high-pressure fuel rails, turbo cooling lines, transmission coolers, and hydraulic brake systems where port consolidation or system reconfiguration is required. Whether you're upgrading a carburetor fuel system to EFI, modifying a turbo oil return circuit, or transitioning fuel lines during an engine swap, these plugs provide a reliable, leak-free termination point that eliminates costly fluid loss and contamination.

Manufactured to strict JIC (Joint Industry Council) specifications, the 6AN 3/8NPT adapter features a hex head design that accepts standard 9/16" wrenches and sockets for positive installation torque without stripping. The black finish resists corrosion in underhood environments exposed to moisture, salt, and thermal cycling, while the conical sealing surface creates a metal-to-metal bond that holds consistent pressure across -40°F to 250°F operating ranges. The 3/8" NPT threads accommodate both AN6 fittings and standard pipe-threaded ports, making this a versatile solution for retrofit applications where original equipment port configurations don't align with modern fuel injection or forced induction demands.

Professional engine shops and race teams rely on this two-pack configuration for complete system builds where multiple unused ports must be secured simultaneously, reducing downtime between service calls. Installation is straightforward—apply thread-seal tape or pipe dope to the NPT threads, hand-tighten, then torque to 25–30 ft-lbs with a wrench to achieve a pressure-tight seal. These plugs are compatible with all ethanol and methanol fuel blends, synthetic hydraulic fluids, and standard engine coolant, making them ideal for street rods, turbocharged imports, drag racing fuel systems, and custom brake line applications. Keep a pair on hand whenever you're diagnosing system leaks or planning port modifications.