Here is a piece of scrap tubing that I used as a test piece for crimping intercooler tubes. I used a Old pair of Vise Grips and welded a bead on one side of a small metal tab that I had laying around (about 1" wide x 1/8" thk. x 1" Lg.. Then I welded the tab to one side and ground a radius in the opposite side of the Visd Grips. After the crimpers were done, I used a Acetylene tourch and heated the end of the tube. While the tube is red hot. Crimp/release/rotate, until the tube is complete.