My double flares look bad

Any chance someone can tell me what’s going wrong here. I’m used a titan 3/16 double flaring tool and nicopp. It keeps giving me this weird stepped flare. I’m not sure what to call this issue so I didn’t know what to look up. I’m doing my best to get a square cut, then I chamfer the outside with a file and chamfer the inside with a utility knife until there’s no burrs.

I’m sort of worried that the screwing motion of the tool is messing with it somehow and instead I need a press tool. What’s weird is I did get one sort of good flare but couldn’t replicate it. It’s also made a few good flares using mild steel line and I haven’t seen the same problem that the nicopp is having. Worst case scenario lines can be steel but it would be nice to use nicopp since the roads are salted here and it’s easier to work with.

The top one is the best, but it looks like the flaring tool was not perfectly perpendicular to the tubing. You must clamp the tubing in the tool very tightly.

Might try using a Q-tip to rub a little oil on the end before forming and be sure to wash it off before use.


I’ve been using the supplied “die lubricant” which is just like a heavy sulfury grease. Is a lighter oil better?

And to old_mopar_guy I’ve been clamping the very end down and then moving it forward and clamping again to make it as straight as possible. Is there anything else I can do to get it more straight or is it just a feel thing I need to get right?

Just a feel thing, and lots of practice.


Are you de-burring the brake line before flaring?


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I’ve always used oil and cannot speak as to the supplied lubricant as I have never tried it.

My tubing tools are all Snap-On and flares have never been an issue so I am not familiar with the Titan tool or its use.

Maybe it’s as old_mopar_guy stated; just a feel thing.

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Not with a proper deburring tool. Just with a utility knife and file which is what I saw in a few videos, so I assumed it would work. Should I just buy that tool or something like it?

ok4450 I’ll probably try oil and brake fluid (separately).

Sounds like I’m just going to need to more practice and probably more tools, as usual

I use a tubing cutter…

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I’ve been using a summit brand mini tube cutter, bad choice since I’m not working inside of the car but it cuts. Do you think I need a different one or should it cut square?

Summit Racing SUM-900500 Summit Racing™ Mini Tubing Cutters | Summit Racing

That should be sufficient, a rotating cutter will cut square.


Try a full size tubing cutter from the plumbing aisle at home Depot.

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A countersinking bit will do a good job of deburring the inside of the tube. By hand or on a drill. It doesn’t have to an expensive one.

Threads like this is why I don’t buy used vehicles .

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I do buy used, but used to be a mechanic (quit that almost 20 yrs. Ago) so I do my own quick inspection, and anything questionable goes to someone a little more current on things than I am.

The only advice I have is, Practice, Practice, Practice and then you guessed it…… more Practice.


I watched the video on Amazon for that product. It doesn’t look like it gives you much to practice with. You put the line in, screw in the tool to make the flare, and then take it out and hope it looks all right.

I’m familiar with the $30 Performance Tool one that is at many auto parts stores. The double flare portion has different size dies that that correspond to different size tube. The instructions are very bad. But if you file the tube off square at the end, then chamfer the outside with a file evenly, and use some oil, and flare an amount of tube that is a bit less than the thickness of the die that you’re using, the die will go down straight and the 1st step will work out. The second step to finish the double flare is done without the die and it’s easy.

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If tubing is first cleaned with soap and water, then lubed per tool spec, and you start w/a neat 90 degree cut at the end of the tube, that’s been filed slightly to remove the burrs, and still not getting a good result? Hmmm … I expect the double flare tool you are using is the problem. Ask your local auto parts store if they have one they’ll lend you, on deposit. You may find that one works smooth as silk. Practice always helps in projects like this, but given the problems you are having by the photos, seems to be more than just lack of practice. Some sort of tooling problem.

Another idea, tube size not supported by that tool or by that tool configuration.


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Interesting vdo. I always thought “double flare” required for car brakes, but vdo implies “inverted flare” method ok. Internet seems to say inverted flare is what car manufacturer’s use in new cars.