Hey 7 bucks...what do you expect? Just a single flare, no bubble or double flare for brakes. Just trying to flare a fuel line. 3/8 worked fine, got a nice even flare. 5/16 was another story. I put the **** in a vice as the tube kept slipping and ended up digging a nice 5/16 donut in the conical ram! Then I read the 'fine print': To be used with Copper, Light weight steel and aluminum....I guess stainless is out of the question. :-( Thats cool, Ill just return it saying it sucks. Yup, HF. I may try and cut a mm off with a hacksaw to remove the work hardened area that the cutter produced, file a chamfer on the edge and even anneal it to red hot with a torch.
The stainless tubing is perfectly round, maybe a hair smaller in OD as the flare vice clamped on it: would a compression fitting work on it? This is the lower pressure (no resistance) return line on a fuel rail. or maybe just a section of EFI hose and some good EFI clamps? Like I said, its just the return line to the surge tank. No head pressure.