Hi, Copper tubing "work" hardens from vibration, becomes brittle and splits/cracks. Leo QCI At 01:50 PM 03/06/2002 -0500, you wrote: >DB, good find! Is this the dimension used on brake lines? > >Also, if I was asked to design a copper brake line, I would make the wall >thickness larger (either by reducing the ID a bit, and/or by increasing >the OD, preferably the 2nd). I am not sure though how this would be >compatible with the fittings, but I think it would work. Point is though >that lack of material strength can be compensated by thicker >material. Also, I would probably specify a higher grade copper alloy, and >I would try to achieve a design factor of at least 2. Problem is of >course, as the pipe gets thicker/stronger material, it may get harder to bend. >D^2 > >At 10:47 PM 6/2/2002 -0700, you wrote: >>My handy dandy McMaster-Carr catalog tells me: >> >>5/16" OD Copper tubing Max Pressure 1197 PSI >>5/16" OD 304 Stainless Max Pressure 3500 PSI >> >>Unfortunately, the type of steel tubing used on cars isn't listed, but the >>type they do list (carbon steel) is about the same strength as 304 >>Stainless. >> >>In service, I calculate that the peak pressure in a panic stop in the brake >>lines of a disk brake car is somewhere in the range of 1200 PSI. >> >>Dick Benjamin > > > >