Yuetai Machinery Technology is mainly engaged in various types of pipe cutting machine products. With the cutting of the blade 6 when the depth of the dent exceeds the wall thickness, the tensile stress on the inner wall of the tube increases rapidly, exceeding the strength limit of the material, and the material on both sides of the blade separates, and the tube is cut. Observing the fracture, it can be seen that there are protrusions on the outer wall of the tube, which increases the diameter of the tube, and the inner wall of the tube forms a contraction, which reduces the inner diameter. This value varies with the angle of the cutting knife of the CNC pipe cutting machine and the degree of wear of the blade. When the! Is larger and the blade wears a lot (the blade becomes blunt), the protrusions and shrinkage produced become more obvious. To cut pipes with a toothed CNC pipe cutting machine tool, the tool must use a high speed. The pipe is a thin-walled workpiece, and it will inevitably vibrate and produce high-frequency noise during work. Therefore, a toothed knife cannot be used. Cutting the pipe with a toothless disc cutter is essentially the tool squeezing and stretching the material until it breaks. There is no sudden change of force during its working process, and it will not produce vibration and high-frequency noise. When the cutter cuts into the pipe, the outer wall material of the pipe is mainly subjected to compressive stress and compressive strain, the material near the tip of the knife is mainly subjected to tensile stress, and the material of the inner wall of the tube under the tip of the knife generates tensile strain. Because the pipe is rotated by the tangential friction force exerted by the cutter, the cutting of the cutter gradually develops inward along the circumference of the pipe. The outer wall material of the tube on both sides of the blade is extruded out under compressive stress, and the tube in contact with the tip of the blade is subjected to compressive stress, but the inner wall material of the tube under the tip of the blade is under tensile stress, making the inner wall of the tube present a 5-shaped protrusion, and the tube under the tip of the blade is under tensile stress. The wall becomes thinner gradually, and dents along the circumference can be seen in appearance.