flaring stainless steel lines
I second the tool question.
I bought a brand new "cal-van" and was junk. Kept pushing the tube out.
Picked up a "National Brass" unit for $5 at a flea market, and it worked perfect the first time.
I do use channel locks or linemans pliers to put about an extra 1/2 turn past as tight as I can get it by hand on the clamp.