Bulkhead Nuts Black -4 2pk

The Bulkhead Nuts Black -4 2pk from Allstar Performance are essential aerospace-grade fittings designed for high-pressure hydraulic and fluid systems in racing, industrial, and precision engineering applications. Sold as a matched pair, these -4 AN (Army-Navy) bulkhead nuts provide secure, leak-free connections in fuel systems, brake lines, and coolant circuits where reliability under extreme conditions is non-negotiable. Whether you're building a competition race car or maintaining critical machinery, this two-pack offers the redundancy and consistency professional technicians demand.

Manufactured in black anodized aluminum, these bulkhead nuts feature the -4 AN thread specification, which correlates to a 1/4-inch tubing outer diameter in standard SAE nomenclature. The anodized finish provides corrosion resistance and durability in harsh environments, while aluminum construction keeps weight minimal—critical in motorsports where every fraction of a pound matters. The pair design ensures matching threads and finishes, eliminating compatibility issues when replacing or upgrading dual-line systems. These nuts mate with standard -4 AN bulkhead fittings and hose ends, meeting industry standards for pressure ratings and flow integrity.

Professional engine builders, custom fabricators, and restoration specialists rely on these bulkhead nuts for fuel cell installations, transmission cooler plumbing, and intercooler setups. The two-pack is ideal for symmetrical dual-circuit builds or as a spare set for emergency repairs in the field. Installation requires only standard wrenches and a basic understanding of AN fitting torque specifications; hand-tightening followed by wrench-tightening ensures proper sealing without over-torquing the aluminum body. Compatible with all standard -4 AN hose assemblies, tubing adapters, and manifold ports.