Radium M14x1.5 Inverted Flare to 6AN Male Fitting, Long

Radium Engineering M14 x 1.5 Inverted Flare to 6AN Male Fitting, Long - Part #14-0118

Honda's factory hard fuel lines end in an M14 x 1.5 inverted flare, and there's no clean way to get a braided AN hose onto one without the right adapter. Radium's 14-0118 is that adapter in the long version: M14 x 1.5 inverted flare on one end, 6AN male on the other, so the factory feed or return line meets an AN hose end with a proper flare seal and no tape, paste, or hose clamp.

What It Is and Why It Works

The fitting is machined from 6061 aluminum and Type II anodized, which makes it compatible with ethanol, methanol, E85, and gasoline. The inverted flare end seats on the hard line's flare the same way the factory fitting did, metal to metal, and the 6AN male end takes any standard AN hose end. The long body gives you room to get a wrench on it and clears surrounding lines and brackets where a short adapter would sit too close to turn. It's the fitting Radium packs in its S2000 rail plumbing kit for the factory feed line, and it's the same connection on the hard lines under a K-series and B-series Civic, which is why it shows up on almost every AN fuel line conversion on a Honda that keeps the factory lines from the tank forward.

Specs

Fitment

Not vehicle-specific. Confirm the line is M14 x 1.5 inverted flare; some Honda return lines and most banjo-style feeds are not, and a flare fitting won't seal on a banjo.

What to Know Before You Buy

No sealant on either end. The flare seals on the metal cone and the AN end seals on the hose end's flare; tape or paste on an inverted flare is how you get a fitting that won't torque and a line that weeps. Hold the hard line's flare nut with a second wrench while you tighten so you don't twist the hard line. Aluminum flares are one-shot compared to steel; if you've had it on and off a few times, look at the cone before you trust it again. If you're converting the whole car to AN with a surge tank, you'll need two of these, feed and return, on the 00-05 S2000 and most B and K chassis.