Figure 1 shows the hydraulic unit bracket cylinder process diagram produced by our factory. The thin wall 27SiMn alloy steel tube with Φ100mm×Φ116mm×1042mm is selected. We use the inner end of the soft claw support and the other end of the tapered top to process the outer and cut limit grooves. It was found that the machined workpiece was flat and out of tolerance, as shown in Figure 2.