AV激情四射国产在线_深夜福利在线观看日韩日韩_欧美va亚洲va在线观_午夜日本美女福利剧场_12萝自慰喷水亚洲网站_国产麻豆美女高潮免费视频_97在线看免费视频_91成人试看福利体验区_国产精品女同一区二区久久_日韩特黄一级毛片在线播放

First of all, we must understand the manufacturing process of quenched and tempered piston rod. It is formed by rolling. A cold hardening layer is formed on the surface of the rolling surface, which helps to reduce the elastic and plastic deformation of the contact surface of the grinding pair, improve the wear resistance of the surface of the cylinder rod, and avoid the burns caused by grinding.

In order to avoid the above phenomena, the piston rod must have sufficient strength and stiffness, and light weight. However,

The electroplating treatment of piston rod is not simple, but also requires a higher technical content, it is necessary to remind everyone about this.

Firstly, the small machining allowance is used to shorten the processing time and reduce the cost of parts manufacturing. Secondly, sufficient machining allowance should be ensured,

Auscultation method of long shaft pump deep well pump with the normal operation of the long shaft, accompanied by sound has always been a certain rhythm and rhythm.