#3 Tube Nut Black

The #3 Tube Nut Black from FRAGOLA is a precision aluminum hydraulic fitting component designed for fluid systems requiring secure, leak-proof tube connections. This AN-standard fitting serves as the essential female connection point in high-pressure applications, making it indispensable for custom fuel systems, brake lines, and transmission cooler installations in automotive and powersports builds. The black anodized finish provides corrosion resistance while maintaining a professional appearance in engine bays and underbody assemblies.

Constructed from lightweight aluminum and rated for 3 AN (5/16-inch dash) tubing with a 3/16-inch compression bore, this tube nut delivers reliable performance in demanding environments. The black anodized finish offers superior corrosion protection compared to bare aluminum, extending the service life of your fluid system while resisting moisture and chemical degradation. FRAGOLA's engineering ensures concentricity and thread integrity, critical factors that prevent tubing migration and catastrophic system failure under vibration and thermal cycling.

Fabricators, race teams, and restoration specialists rely on this fitting for fuel injection systems, custom cooling loops, and brake line reroutes where OEM connections don't suit modified engine bay layouts. Installation requires no special tools beyond a standard wrench—hand-tighten first, then torque to manufacturer specifications to ensure proper sealing without cross-threading. Compatible with standard 3/16-inch aluminum tubing and FRAGOLA's full range of AN adapters, this tube nut integrates seamlessly into modular fluid systems and supports both street and competition applications.