At present, the processing times has been changed from 12 to10. Thus central distance tolerane of small bore after improvement has been maintained within 0.02mm, the quality of withdrawal ring has been ensured and prodution efficiency has been increased.

• 改进前工艺是12道工序；改进后工艺是10道工序。 工艺改进后小孔中心距公差尺寸达到0.；02mm以内；保证退料环质量；提高了生产效率。