This passage has introduced the features of cubic boron nitrite as well as the successful methods for boringvalve body, moreover, has listed the technological parameters in practical processing.
这里介绍了立方氮化硼刀具的特点和用于镗削阀体的成功方法，并列出了实际加工的工艺参数。
2
This paper introduces a new device of boring the valve-seat and gives the relatively detailed explanation of the device's structure and working-process.