I intend to either make or buy a tubing bead roller to produce that bead on all of my turbo/intercooler plumbing. My existing bead roller won't work too well, to do it.
Ready made tool:
One guy on the turbo forums used an old vise, and a set of homemade dies to roll the needed beads. Simple, and certainly dirt cheap to do, if you have access to a lathe to make up the dies from scrap material. I would probably make up a smaller die set, so that it would be able to fit inside of the coolant tubing.