Abstract: There is disclosed a novel crimp connection for directly joining metal tubes together. The crimp connection includes at least one circumferential crimp for locking or fixing the tube end portions together, which locking crimp will have varying lateral and radial dimensions. The connection may also include a second type of circumferential crimp for sealing the tube end portions together, which sealing crimp will preferably have substantially constant lateral and radial dimensions; and may include a third type of crimp for stabilizing the sealing crimp against radial and axial forces applied to the tube end portions.