j) In case the ink flowing groove becomes shallow

• The pen tip of a ballpoint pen has a structure in which a "pipe" of a metal (mainly stainless steel) with grooves through which ink flows carries a "ball" of cemented carbide. Therefore, when writing with a strong writing pressure repeatedly or a strong impact is applied to the pen tip, the ball scrapes or deforms the "ball supporting part". As a result, as shown in the above figure, the "ink flowing groove" becomes shallow, ink is difficult to flow, depending on the situation, it cannot be written.