I side with Dick Benjamin on this issue. Reason being is this: We use a large variety of material in the aircraft industry and the prime example I can think of is control cables. Without exception, stainless cables are not...NOT...as strong as standard steel ones. I dont know the SAE spec of them offhand, but they are at my disposal at any time, we keep material certification specs on ALL the materials we use. The only time we use stainless cables are for seaplane or floatplane use and even at that, the life of the cable becomes somewhat irrelevant, as these things will be removed and replaced before they ever get to the danger point of weakness. As far as the brake line issue, it is no doubt true that the manufacturers do add a rather large safety factor when they design these cars, Im sure that with things like brake lines theres a huge margin of overkill with the material strength. On the specific subject of steel brake lines.....I have always and always will use standard issue steel lines. No copper, no stainless, no unobtanium, nothing else. On the subject of flexible hoses, an aftermarket stainless flex hose is great, since the manufacturer is taking the liability risk and hopefully they are SAE approved for automobile use. Otherwise, I have used many many store bought lines as well as taken store bought lines and cut the ends, reflare them and have had ZERO trouble with them. A properly done double flare and correct hardware will work every time. Just my 3 cents, those of you who DO wish to use other stuff, well feel free......just please stay IN FRONT of me in traffic please. take care all Mikey 62 Crown Coupe