当需要检查1个铸件表面沉孔的深度时发现,零件沉孔的深度从加工底面起必须保持在12．7mm,见图1。但是,由于零件的顶部是铸造毛坯,无法使用深度千分表。设法解决这个问题的方法是使用1个钻杆和1个千分表。把1个可以到达沉孔底部的钻杆放到千分表和12．7mm的量规中间,把 When it is necessary to check the depth of a counterbore in a cast surface, it is found that the depth of the counterbore must remain at 12.7 mm from the bottom of the machined surface, see Figure 1. However, a depth gauge can not be used because the top of the part is cast as a blank. The solution to this problem is to use a drill pipe and a dial gauge. Place a drill pipe that can reach the bottom of the counterbore into the middle of the dial indicator and the 12.7 mm gauge