V1 Double flare or single flare brake lines

[Tim Moland]

I'm doing some brake work which will require me to make some custom brake lines. I'm going to be installing line lock on the front brakes. Do I need to make single flare, double flare, or bubble flares on my lines. What size are the lines?(I'm guessing it's measured by the O. D.) Are the DF lines steel, or aluminum? Any help is appreciated.