Abstract: A one-piece unitary compression clamp for securing a pipe or tube on a fitting. The clamp may include at least one inward deformation that provides an interference fit between the clamp and the pipe or tube. Consequently, the clamp cannot fall off the pipe or tube before being permanently crimped, and the fitting is prevented from falling out of the tube. In a second embodiment, the clamp includes an ear for crimping the clamp to the tube, and a tongue within the clamp and overlying the mouth of the ear to provide uniform compression around the entire tube. In a third embodiment, the clamp includes stop tabs that hold the pipe at a stand-off from the end of the clamp.