RBS recommends anyone putting together there own stainless steel braided hoses needs to own a set of these alum. vise jaws. They are made from soft cast alum. so they don't scuff or scratch your fittings and have reliefs cut into them to hold the fittings securely while you get the hoe put onto the fitting.
One more benefit of these jaws are that they use a magnet on the back side of them to hold them to your bench top vise.
Sold in pairs.