在管子车床上车岩心管、套管，以往每车一头丝，要在刀杆上来回更换三次刀头，既费时，又费事，为此，自制了一种活动三用刀具（如图所示）。即车内圆、车丝、光丝尖三个工序，所需刀具装在一个活动刀头上。每完成一个工序，反拧120°，再继续第二个工序。使用证明，在φ89毫米以上管径中，刀具刚性 In the tube lathe car core tube, casing, in the past every car a wire, to change the cutter head back and forth three times, both time-consuming and costly, for this, homemade a three-use tool (as shown ). That is, the inner circle, the thread, and the light tip are three processes, and the necessary tools are mounted on a movable cutter head. After each process is completed, reverse 120° and continue with the second process. Proof of use, tool rigidity in pipe diameters above 89 mm