First, you need a tubing cutter to, uh, well, cut the tubing.
That's the only way to make a square end.
second, when you go to put the fitting together, the nut slides
onto the tubing. And second, a "ferrule" which looks kinda like a
mini wedding band. When you tighten the nut, the ferrule
compresses onto the tubing. Soak the nut, ferrule, and fitting
with penetrating oil, so it will seat tighter.
Christopher A. Young
You can\'t shout down a troll.
Click to see the full signature.