brake line sizes

[black heartbeat]

hey it turns out I need to replace my rear brake lines, you know the ones that go along the top of the axle and whatnot? Well they are so freaking rusted that I can't seem to get a good measurement on the brake line, and I can't find anywhere online with the specs for it. From the best I can tell with the micrometer, I'm dealing with 3/16" lines with 1/2" flare nuts. I was just wondering if someone could possibly verify this for me?