技师将塑料管套在芯棒上以便弯曲成型。

The technician slipped the plastic tube over the ___mandrel to bend it into shape.

工匠将金属片缠绕在心轴上成型。

The craftsman wrapped the metal sheet around the ___mandrels to shape it.

她在心轴上调整金戒指以获得完美的尺寸。

She adjusted the gold ring on the ___mandrel to get the perfect size.