A fluter is used to form little ripples, called "flutes," into the edges of sheet metal. When a piece of metal has a curved bend, the outer edge of the bend is longer than the bend itself, so the piece tends to warp. Flutes "shorten" the outer edge so that the metal will not warp. This set was made from a standard pair of Vice Grips with three small steel rods welded onto the jaws by the factory.
I needed a fluting tool that could make nice, large flutes into metal that was too thick for the normal fluters. I made this set from a piece of half-inch steel rod cut into three pieces. I ground the tips as best as I could with an angle grinder, then put each piece into the chuck of a small drill press. With the piece turning in the drill I finished the part with a hand file. Next, I drilled some holes in the pieces, then used a long, bent bolt as the hinge pin. The reason that there are several holes is so that I can get extra leverage or longer "reach" as needed.