工人在车床上使用心轴来精确加工金属管。

The worker used a ___mandrel on the lathe to precisely shape the metal tube.

车工将工件固定在心轴上以便加工。

The lathe operator clamped the workpiece onto the ___mandrel for machining.

工人们将金属管套在芯棒上，以便进行弯曲加工。

The workers slid the metal tube over the ___mandrel to bend it into shape.