AN Fuel Line Fittings — 37° JIC Flare

Product Description

AN (Army-Navy) fittings — formally specified as SAE AS4395 — use a 37° JIC (Joint Industry Council) flare instead of the 45° flare used in HVACR. The 37° angle was selected by the US military during WWII for higher pressure capability and reduced sensitivity to over-tightening — and AN fittings remain the standard for high-pressure hydraulic, fuel-line, oil, brake, and power-steering plumbing in motorsport, military, aerospace, and high-performance automotive applications. Our brass AN fittings are CNC-machined from C36000 free-machining brass to SAE AS4395 dimensional requirements, with the 37° conical face finished to mirror smoothness for reliable leak-tight sealing at pressures up to 3,000 PSI. The standard AN size system uses dash numbers (-4 through -12 for our range) where each dash represents 1/16" tubing OD: -4 AN = 1/4" OD tubing, -6 AN = 3/8" OD, -8 AN = 1/2" OD, -10 AN = 5/8" OD, -12 AN = 3/4" OD. Threads are UNF (Unified National Fine) to SAE specifications — distinct from NPT or BSP — and use the 37° conical face for sealing rather than thread interference. AN fittings are reusable: the flare on the tubing can be re-mated multiple times without sealant or thread tape. Our standard AN range includes male and female straight unions, 45° and 90° elbows, tees, crosses, AN-to-NPT and AN-to-O-ring boss (ORB) adapters, swivel adapters, bulkhead fittings for firewall pass-throughs, and reducing unions for mixed-size connections. Anodized aluminum colored AN nuts and adapters available for retail motorsport applications (red, blue, black). Custom finishes (gold, satin, polished) on request.

Available Variants

This product is offered in the variants listed below. Specify the variant(s) you need in your RFQ.

Technical Specifications

Commercial Terms