Also known as rollerball pen or rollerball pen. The pen barrel and pen cover of the roller-ball pen are made of plastic injection molding, called all-plastic roller-ball pen; the pen cover made of stainless steel stamping and grinding is called the semi-steel roller ball pen; the pen-holder and pen cover made of stainless steel are called all-steel roller ball pen. The all-plastic type is basically one-time use, that is, the ink is used up and it is scrapped; the semi-steel type and the all-steel type mostly adopt a replaceable refill structure. The tip of the treasure pen is divided into two types: shell type and needle tube type, which are made of copper alloy, stainless steel or engineering plastics. The balls are mostly made of stainless steel, cemented carbide, or alumina. The diameter of the ball with middle handwriting is 0.7 mm, and the diameter of the ball with fine handwriting is 0.5 mm. There are two types of water storage: fiber bundle water storage and fiber bundle-free water storage. The colors of the ink are red, blue, black, green, etc. The ballpoint pen has the characteristics of a fountain pen and an oily ballpoint pen. It has smooth and smooth writing and uniform lines. It is an ideal writing tool.
In addition to the above classifications, there are common classifications based on ink color and pen structure.
