I recently made some custom tooling for creating beads on my intake piping and a radiator hose coupler (http://mearcat.blogspot.com/2017/09/intake-and-radiator-piping-beads.html). I now had a requirement to do the same for some fuel lines. The fuel line pressure is over 30psi from the EFI fuel pump to the engine, which is far more pressure than the intake or coolant systems so they need a bead on the ends of the steel fuel lines (as well as a hose clamp) to prevent the rubber hoses from leaking.
As opposed to the larger 25mm radiator and 50mm intake pipe, the fuel lines I will use for both feed & return are small : 6.5mm ID. The 8mm fuel line (I used 8mm brake line / "bundy tube" for the fuel line) and if as per the intake piping, I made some dies to crush a bead into the tube using normal steel, I figured a thin 3.5-4mm diameter rod inside the tube may easily bend so I chose to make die pieces in harder stainless steel instead of machining steel.
The same process as before was done - machining a male & female die piece on the lathe and welding the pieces to a couple of steel plates that replaced the vice jaws. Because the fuel lines under the car are quite long, I welded the die pieces horizontally to the vice plates to make it easier to hold and twist the fuel lines when forming the beads.
The tube is placed over the male die piece and the vice tightened slightly, loosened and the tube rotated slightly and tightened again.
I was very happy with the result on this test piece of fuel line..
The formed bead was a very similar profile & size compared to a factory bead on the fuel rail as seen in the photo below. The diameter of the end of the tube ends up being reduced ever so slightly, but it's only a ~0.3mm reduction so not a concern for fuel flow.
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