In normal use, the piston rod produced by the piston rod manufacturer bears alternating loads. The surface of the piston rod is sealed with reciprocating friction at a position of 50mm 770mm. Therefore, the piston rod requires high hardness and wear resistance. The structure of the piston rod is relatively simple, but the ratio of length to diameter is large. It is a slender shaft part with poor rigidity. In order to ensure the machining accuracy, rough turning and finishing turning should be separated, and tool holders should be used for both rough turning and finishing turning to reduce the deformation of the work piece during the machining process, and it ends at b. When selecting the positioning datum, in order to ensure the coaxiality tolerance of the parts and the accuracy of the position of each part, all the machining processes are located in the two center holes, which conforms to the principle of unified datum. When grinding the cylindrical surface, the work piece is prone to tooling, elastic deformation and affect the accuracy of the piston rod. Therefore, the center hole should be ground to ensure that the center hole is clean, the tightness between the center hole and the top should be appropriate, and good lubrication should be ensured. Grinding wheels are generally selected: abrasive white corundum (WA), grain size 60#, soft or medium hardness, and ceramic bond. Except for the width of the grinding wheel should be narrower, in order to reduce the radial grinding force, pay attention to the grinding parameters during processing. Choose, pay particular attention to the choice of grinding parameters. The grinding depth should be small. When grinding an outer diameter of 50mm×770mm and a taper of 1:20, two processes must be carried out separately. When grinding a 1:20 taper, before grinding the work piece, the sample must be ground and the qualified parts must be inspected. The 1:20 inspection of the tapered surface is performed by standard NGC. The contact surface should not be less than 80%.

In order to ensure the stability of the machining accuracy of the piston rod produced by the piston rod manufacturer, manual straightening is not allowed during the entire machining process. When nitriding, the threaded parts should be protected by protective devices.