The ink flowed into the tip of the pen which contained the stainless steel ball.

墨水可以流入装有不锈钢球的笔尖。

With the help of state-of-the-art Swiss watchmaking machines, he developed a method for mass-producing tiny stainless steel balls to within a fraction of a millimeter.

在最先进的瑞士制表机器的帮助下，他发明了一种大规模生产微小不锈钢球的方法，精确到零点几毫米。