#12an Fitting - Black

The MEZIERE #12 AN Fitting – Black (model WP12012S) is a straight-through adapter designed to connect two 12 AN male ports equipped with O-ring seals. This aluminum fitting is anodized black to resist corrosion and provide a finished appearance in high-performance cooling and fuel system applications where reliable, leak-free connections are essential.

The straight male-to-male configuration allows direct coupling of two hoses or hard-line fittings without orientation constraints. The O-ring seals on both ends create a positive hydraulic lock that eliminates dependence on traditional thread-locking compounds, reducing assembly time and improving seal integrity under pressure cycling. At 0.13 lbs and compact dimensions (3.7 x 1.6 x 5.2 inches), this adapter integrates seamlessly into space-constrained engine bays while maintaining the flow capacity of 12 AN plumbing. Black anodizing protects against oxidation in environments where moisture and thermal stress would compromise bare aluminum, extending service life and maintaining aesthetic consistency across custom cooling and fuel system builds.

This fitting is ideal for custom high-performance cooling systems, fuel delivery systems, and hydraulic applications in street rods, race vehicles, and specialty automotive projects. Whether routing additional cooling lines or creating mid-run coupling points in fuel or coolant circuits, the 12 AN standard ensures compatibility with industry-standard hose and hard-line fittings. The O-ring face seal (ORFS) connection type has become the preferred standard in modern performance applications due to superior reliability compared to NPT threads in pressure-cycling scenarios.