I do it all the time - have a few rolls of the copper plated steel tube in different sizes. The idea of going to the nearest brake place (4 hour round trip) and getting them to make a pipe up while I wait (or worse, come back later) is just impossible. But I maintain a fleet of farm trucks so when comes in with a brake problem there's no hanging around. But also for fixing/restoring my own old girls they're so quick, wash and cheap to make why buy? Always just reuse the fittings, good not to use cheap open Enders or you start the slippery slope to using Multis then having to get new fittings... Do have the rigid tool though which is nice use.
Also good for air, fuel and any other metal lines though
