#4 An Aluminum Tube Nut

The #4 AN Aluminum Tube Nut by Aeroquip is an essential fastening component for high-performance fuel, oil, and coolant line systems in custom and modified vehicles. Mechanics and enthusiasts rely on these fittings when building or upgrading hydraulic and pneumatic circuits where precision connections are non-negotiable. Whether you're assembling a custom fuel injection setup, turbocharger feed lines, or a complete engine bay fluid management system, this tube nut delivers the reliability that separates a professional build from a hasty repair.

Manufactured from lightweight aluminum, the #4 AN fitting reduces unsprung weight while maintaining structural integrity under pressure cycling. The AN (Army-Navy) specification ensures consistent thread geometry and sealing surface angles across all manufacturers, meaning this Aeroquip nut mates reliably with any standard #4 AN tubing and hose assemblies. The compact 2.2 x 1.1 x 3.7 inch footprint and minimal 0.07 lb weight make it ideal for space-constrained engine bays where every ounce and inch matters in a modified platform.

This fitting is essential for anyone building fuel systems, intercooler plumbing, or custom coolant loops on turbocharged, supercharged, or heavily modified engines. Its aluminum construction makes it popular in motorsport and street-rod applications where weight savings compound across multiple systems. Always pair #4 AN tube nuts with matching #4 AN tubing and hose to ensure proper seal and prevent leaks under operating pressure—Aeroquip's precise manufacturing tolerances guarantee consistent performance across all your fluid delivery lines.