double and inverted flare

I'll add that brake tubing in newer cars (~2000+) usually uses "bubble flares". You can actually form these with a normal "double flare" tool, just use the backside of the die (not the normal countersunk side). It is actually quicker since you don't do the 2nd press with the cone. You can find youtube videos showing how. Why do so? A proper bubble flare tool costs ~$100.