343-03-03 -3 male to 9/16" -18 male inv

Speedflow SF343-03-03 | -3 AN Male to 9/16"-18 Male Inverted Flare Adapter

The Speedflow SF343-03-03 is a precision-machined -3 AN male to 9/16"-18 male inverted flare adapter, designed to connect -3 AN braided line systems to components with a 9/16"-18 inverted flare (double flare) port. The 9/16"-18 inverted flare is one of the larger OEM brake line thread standards, commonly found on the outlet ports of larger master cylinders, brake boosters, and proportioning valves on American muscle cars, hot rods, and performance vehicles.

Product Specifications

• Part Number: SF343-03-03
• AN End: -3 AN male
• Inverted Flare End: 9/16"-18 male inverted flare
• Weight: 28g
• Series: Speedflow 343 — AN to 9/16"-18 Inverted Flare Adapters
• Compatible With: Standard -3 AN hose ends and 9/16"-18 inverted flare ports
• Barcode: 9342122002656

Applications

The SF343-03-03 is a critical adapter for brake system AN conversions and custom line fabrication, including:

• Connecting -3 AN braided brake lines to master cylinders with 9/16"-18 inverted flare outlet ports
• Brake booster and proportioning valve connections on factory-style brake systems
• Hot rod, muscle car, and classic vehicle brake line upgrades from steel tube to AN braided
• Holden, Ford, Chevrolet, and GM vehicle brake system AN conversion builds
• Any application bridging -3 AN braided lines to 9/16"-18 inverted flare brake components

9/16"-18 Inverted Flare — Large-Port Master Cylinder Standard

The 9/16"-18 inverted flare is the largest of the common OEM brake line thread standards and is typically found on the primary outlet ports of larger tandem master cylinders and brake boosters on American V8-powered vehicles. Getting this thread size right is critical in a full AN brake line conversion — the SF343-03-03 provides a clean, single-piece adapter solution that eliminates the need for custom tube fabrication at these large-port components, ensuring a leak-free, professional result.

For other AN to inverted flare sizes, see our SF340-03 (-3 AN to 3/8"-24), SF341-04 (-4 AN to 7/16"-24), and SF342-03-03 (-3 AN to 1/2") listings. Sold individually. Weight: 28g.