Rigid flaring tool scores tubing

(old message removed)

To my eye the flare looks odd. Are you sure this is an AN (37 degree) flaring tool, not an SAE (45 degree flare) tool?
Doesn't answer your question, I know.

I think every flare tool that forms the flare by pressing it into the die block has that problem. If everything else is good I would just burnish it with some scotch-brite and move on.
I personally use a 400-F tool which forms the flare above the die block, works like a dream and makes a perfect flare every time.

A light coat of oil on the contact parts before EVERY flare will minimize markings. As others have mentioned - ensure the flare is not 45*. (Looks like it could be a bit wide.)

I had a similar problem with ridges being pressed into the tube when I tightened the die halves. Try wrapping a turn or two of masking tape around the tube where the tool grips it. That worked for me.

Mine does the same thing, not sure how to avoid it the way the tool is designed. I just lightly sanded mine and moved on, the sealing surface seemed to turn out well. So far not a hint of any leaks on any of my flares (fingers crossed) on 27 hours thou so time will tell.

I took some 600 grit on a popsicle stick and "polished" the edges of the die on my Parker. Like Walt, I also just burnish the finished flare before using, outside and around the outer perimeter of the flare. "deburring" at it's finest

Are you following tried & true

http://www.gen-aircraft-hardware.com/images/pdf/GAHco_Flaring_Stainless_Tubing.pdf

Let me know what Rigid has to say

Rigid will hopefully enlighten the situation

Rigid 37

I have the 37 degree Rigid Flaring tool and mine leaves a seam too, if I clamp down with too much force. After playing around with it, I found the sweet spot, both for clamping force and for length (i.e. not necessarily flush with the die) to get the proper flare diameter. If I have a little seam, it's usually only cosmetic and I polish it off with my wheel. I can't say that other tools work better or worse, because I haven't tried them. However, I've learned to use mine well. Be sure to add some BoLube everytime you make a flare. As far as the multi-step process illustrated, I find that I can use a "good quality" pipe cutter with success if I go at it slowly. It gives a nice, square cut, which is easily deburred and ready for flaring. You'll find that the process above doesn't help when you need to cut in tight spaces. Keep playing with it 'till you get it. It took me several tries, but now my 2 year-old daughter likes to play with all the little curvy bits of improperly flared/bent tubing, which I keep just for her...