Brake Line Help

I ran into a little problem while trying to replace my rubber brake hoses. The passenger side came off fine but I stripped the driver side. I got it off with vice grips but now I need to either buy a new line or but on a new flare nut.

If I go the new nut route, what type of flare are these lines and what size flare nut do I need? It is the flare nut that connects the hardline to the soft rubber caliper line.

Also, harbor freight has a flare tool but it is for double flaring. If this line is not double flared, can I still use this tool?

Thanks!

Also, if I just go the new brake line route, what size line do o need? I believe their metric but does anyone have the specifics? This is the driver side front line.

Thanks!

I was using brake line wrenches but they were standard. So, I used 7/16 on the first and started to strip it. I went and bought a 11 mm brake wrench and got the other side off fine.

So, the flare nut has gotta be a metric size. Just in case I replace the line, does anyone else have any other input on the size?

Thanks