Particularly when a long cylinder with a small internal diameter is bored,the bar holding the tool must be long and slender and cannot be as rigid as the thick, stocky(短而粗的)tools and tool post used for most turningParticularly when a long cylinder with a small internal diameter is bored, the bar ( 刀 杆） holding the tool must be long and slender and cannot be as rigid as the thick, stocky（短而粗的） tools and tool post used for most turning