我国贯彻的GB1160—74圆形油标按视孔“d”(见图1,表1)制定的规格有12、16、20、25、32、40和50共七种。目前我厂生产的产品经常选用12、20和32三种圆形油标的国标。过去我厂对圆形油标安装孔(见图2)的加工方法比较复杂一般采用先钻铰“d_1”孔至公差后,再以“d_1”孔作导向,利用沉钻加工“D”沉孔,然后用角铣刀加工30°倒角。用此法加工图2安装孔工序较多,费工、 China’s implementation of GB1160-74 round oil standard according to the hole “d” (see Figure 1, Table 1) to develop specifications 12,16,20,25,32,40 and 50 total of seven. At present, the products I plant often choose 12,20 and 32 three round oil standard GB. In the past I plant on the round oil hole mounting holes (see Figure 2) processing methods are more complex commonly used first drill hinge “d_1” hole to tolerance, and then “d_1” hole for guidance, the use of submerged drilling “D” Hole, and then use angle milling cutter 30 ° chamfering. Use this method to process Figure 2 mounting holes more processes, labor,