eli5 how is the ball in the tip of the Pen is made/manufactured, how something can be made so small, yet so perfect?

Question

like, it is not only about ball of the Pen, but also about many things, like how small springs are made, and etc.

In: 8

Answer 1

I don’t think the issue is so much how they can be made with such precision, but how they can be made so cheaply still with adequate precision. See also: run-of-the-mill semiconductor chips which sell for a few cents.