Thread: AN Fittings

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It's about time to start plumbing the brake and fuel lines . Is ther a link on the how to and what not to for and a sizing chart?

brake lines should be done in hard steel ( or stainless ) and must be double-flared. The general concensus on double flaring it that it is dam hard to do it right, so you are better off to buy pre-bent pre-fabbed lines. As for the AN fittings for the rest, You need to know what size hose you are using first ( I think the #s refer to 1/16s of an inch... IE. 6AN would be 3/8" inside diameter. Then you need to know what you are screwing the fittings into... it might be a NPT thread, or a standard thread. The fittings for the carb and fuel pump are special critters. My best advice for AN fittings, is that unless you have a speed shop with a good selection ( and they are reasonable towards exchange ) then grab a Summit catalog. Order anything you know you'll need, anything you think you'll need, and anything which you don't think you'll need, but aren't 100% sure. When you are done, just send the extras back for refund. Don't be shy with the wallet, cause the dam critters are 7-14$ ea. Just remember, you'll be returning what you don't use.

Another possibility is dress-up fittings. They are just dressy hose clamp covers. One thing: if you put hose clamps on braided stainless hose, you'll need to tighten it again the next day, and the next day after that or they'll leak. True braided stainless hose works best with the real fittings. Curved-jaw cable cutters work well to cut it. Wrap the hose in electrical tape, then cut thru the center of the tape, and that keeps the hose strands from fraying. If you don't have the cable cutters, then clamp the hose lightly in a vice and cut thru the tape with a hack saw.

Double flaring is super easy if you have a nice tool. For stainless steel, you pretty much need a hydraulic flaring tool, but you might be able to get away with a hand crank if your lines are small. I haven't tried in my hand crank flaring tool yet. For the best of the best for hand flaring tools, look to Ridgid.

I have the kit at the end of the list: http://www.coastaltool.com/cgi-bin/S...htm?E+coastest

Never split a line while doing a double flare. The flaring buttons provide a measurement so you get the right amount of overlap every time.

The most important thing when doing double flares, or any flare for that matter, REAM REAM REAM.

If you do go with stainless, I recommend going with compression fittings made by Swagelok.

> You need to know what size hose you are using first ( I think the #s refer to >1/16s of an inch... IE. 6AN would be 3/8" inside diameter.

One minor correction to an excellent treatise. AN hose is specified in "nominal" sizes that correlate to comparable copper tube sizes. -6 AN would be 3/8" but it's actual ID would be the same as the ID of a 3/8" tube size, or .340" instead of .375" which would be the OD of the tube.

Bob