[Aussie Mike]

If you are going to use a tube nut and a flare tool just remember that AN fittings are a 37 degree flare where as your regular flares are a 45 degree seat. If you use the regular off the shelf tool then you may have problems making the flare seat and seal properly.

You can do it by starting the flare with the regular flare tool and then using a steel AN fitting tghtened into the tube nut to finish it and set the seat at 37 degrees.

Cheers