Abstract: An improved method of making a cross joint between different size pipes is provided. A punch, die and a pressing machine are prepared. The punch includes a center rest for receiving a small pipe, a curved slot and a curved surface for transforming an end of the small pipe. Under the actuation of the pressing machine, the end of the small pipe is transformed into an arcuate configuration which is identical with the inside curvature of a large pipe. Simultaneously, a curved bead is formed on the small pipe remaining circumferentially equal distances from the resultant arcuate edge of the small pipe. This distance is substantially the same as the wall thickness of the large pipe. Utilizing the arcuate edge and the curved bead, the small pipe and the large pipe are welded or brazed together, resulting in a cross joint having no protrusion into the large pipe space.