AN to hardline fitting

AN hardline fittings provide the correctly formed connection between rigid tubing and AN fuel system components. Evil Energy fuel line fittings help builders transition aluminum or stainless steel hardline to AN plumbing without adding an unnecessary chain of adapters, supporting cleaner routing in EFI fuel systems, LS swaps and custom engine bay layouts.

This collection includes male and female compression-style tube adapters, plus AN tube nut and sleeve sets for 37-degree flared hardline. Selected compression adapters use an aluminum fitting body with a brass ferrule and are offered in combinations such as 4AN to 1/4 inch, 6AN to 1/4, 5/16 or 3/8 inch, 8AN to 1/2 inch and 10AN to 5/8 inch. Tube nut and sleeve variants extend from 3AN with 3/16-inch tubing through 16AN with 1-inch tubing.

Choose by the tube’s actual outside diameter, the required AN dash size and whether the mating connection is male or female. AN size and tube OD describe different sides of the fitting, so never select a part from the AN number alone. For other connection styles, compare Evil Energy AN fittings and adapters or plan the complete routing with compatible fuel lines and fittings.

How Do I Choose the Right AN Hardline Fitting?

Start by identifying what must connect at each end of the tube. Measure the hardline OD with a caliper, check the gender of the mating AN fitting and then select the corresponding AN size. The fitting style determines how the hardline end must be prepared.

A 6AN fitting does not automatically fit every tube described as a 6AN fuel line. Evil Energy compression variants pair 6AN connections with several different hardline ODs, including 1/4, 5/16 and 3/8 inch. Always order from the complete AN-to-OD variant label rather than matching only one number.

How Should Hard Fuel Lines and Fittings Be Installed?

Plan the complete route before cutting the tube. Keep hardline away from exhaust heat, sharp edges and moving suspension or steering components. Support long rigid sections with suitable clamps, and use a flexible hose section where engine movement or service access requires the line to move independently from the chassis.

1. Verify all three measurements: confirm tube OD, AN size and male or female connection before assembly.
2. Cut and deburr the tube: make a square cut and remove sharp edges without scratching or deforming the sealing area.
3. Inspect the hardline: do not assemble a fitting over a dented, deeply scratched or out-of-round tube end.
4. Use the correct preparation method: assemble compression fittings according to the ferrule orientation shown for the product. For tube nut and sleeve fittings, slide both parts onto the tube before creating the 37-degree flare.
5. Protect the sealing surfaces: the 37-degree flare and compression ferrule create the seal. Do not use thread tape to compensate for a damaged flare, incorrectly sized tube or misaligned connection.
6. Secure and test the system: clamp the hardline to control vibration, pressure-test the completed assembly and inspect every connection again after the first operating cycle.

Complete rigid-to-flexible transitions with correctly matched AN-to-AN fittings. If the system requires flexible, fuel-compatible hose between the chassis hardline and engine components, review the available PTFE fuel line kits and verify that every hose end matches the selected hose construction.