图1所示零件上均布29个尾部为锥形的孔,钻孔后要求保证φ6.5mm孔的深度为4_0~(+0.48)mm。由于该孔底面不是平面,因而无法用万能量具如游标卡尺等检测,鉴于除了检验员外,还要求生产者进行自检,故需要一种较为简便的测量方法以提高工效。我厂现采用钢球检测法,即在孔中放入一个φ5.5mm钢球后,用游标卡尺测量钢球顶部与零件 The parts shown in Fig. 1 are evenly distributed with 29 tapered holes at the tail. After drilling, it is required to ensure that the depth of φ6.5 mm holes is 4 - 0 to (+0.48) mm. Since the bottom of the hole is not a flat surface, it can not be detected with a universal gauge such as a vernier caliper. In addition to the inspector, the producer is also required to perform self-test. Therefore, a relatively simple measurement method is needed to improve work efficiency. I plant is the ball test method, that is, after putting a φ5.5mm ball in the hole, measuring the top of the ball and the parts with a vernier caliper