SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING The operation is characterized by the unchanged equipment, unchanged workpiece and continuity. For example, a batch of workpieces is machined first on a lathe, and then on a milling machine. Obviously, two operations are involved. Fig. 6. 1 shows the machining of the center hole and recess of a recess退刀槽 flange. f a batch of the workpieces areflange法兰盘 machined consecutively by drilling, boring‖bore镗孔 holes and boring recesses with three different cutting tools at the same workplace(e.g.a lathe), it is a single operation. If these holes are drilled on a lathe and then bored on another, the machining of the workpieces will consist of two operations instead of oneSCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING The operation is characterized by the unchanged equipment, unchanged workpiece, and continuity. For example, a batch of workpieces is machined first on a lathe, and then on a milling machine. Obviously, two operations are involved. Fig. 6.l shows the machining of the center hole and recess of a flange. If a batch of the workpieces are machined consecutively by drilling, boring holes and boring recesses with three different cutting tools at the same workplace (e.g. a lathe),it is a single operation. If these holes are drilled on a lathe and then bored on another, the machining of the workpieces will consist of two operations instead of one. recess 退刀槽 flange 法兰盘 bore 镗孔