I'll agree with Vince and Centerline too..
If you are having trouble flaring it, it is not designed to do what you want it to.
Use the 37 degree tool and the right fittings. Or get the pre annealed tube. Don't play metallurgist with something as critical as brakeline. Even if you do get it to flare, what's to say you don't have a failure later from uncontrolled annealing methods.
There are a bunch of threads here about flaring stainless. Most all say the same thing.