How Does a Ballpoint Pen Work?

by Ann Johnson; Updated September 26, 2017

Parts That Make the Ballpoint Pen Work

We use ballpoint pens in our day-to-day life. They are used at school, home and the office. Most of us know ballpoint pens don’t write very well when the writing tip is higher than its opposite end. That is because it is primarily a gravity-reliant writing instrument. The ballpoint pen has four basic parts that enable it to work; the writing tip, socket, ink reservoir and the connecting tube.

Inner Workings

There is a reason for this style of pen to have the name “ballpoint”. Its writing tip is actually a tiny ball that is fitted into a socket, allowing it to roll around freely. The small ball can be made of a steel, tungsten carbide or brass. A narrow tube, called the ink reservoir, holds the ink, and a connecting tube connects the ink reservoir to the socket and ball. When we hold a ballpoint pen in our hand and begin to write, the ball rolls around in the socket, moving ink from inside the pen to the writing paper. Because of its design, the ink used in this type of pen tends to be thicker and sticky. A thinner ink would have a tendency to leak out from where the ball and socket fit together.

Basic Ballpoint Pens

The ballpoint pen has an outer cover that surrounds the ink reservoir. This is the part of the pen that we hold in our hand as we write. Some covers resemble a thick, plastic, straw-like object. Other covers are designed to fit the contours of our hand, and some are embellished with rubber-like grips. The writing tip of a basic ballpoint pen sticks out of one end of the pen’s cover. On the opposite end, a small button-like cap is inserted into the end of the pen. Removable caps to cover the writing tips are often included to prevent the ink from drying out.

Mechanized Ballpoint Pens

Some ballpoint pen designs are more elaborate, and instead of the removable cap, they have a clicking mechanism. The mechanism moves the writing tip in and out of the cover when the user pushes the button that is located on the opposite end of the pen. This push button replaces the small cap found on the ends of non-mechanized ballpoint pens.

Gravity and Ink

Some ballpoint pens are not completely dependent on gravity to work. In those, designs there is a constant pressure applied behind the column of ink, enabling the writer to use the pen even if the writing tip is elevated. Typically the ballpoint pen requires a certain amount of pressure to be applied in order for it to work. It lacks the free-flowing quality found in some other pen designs.

About the Author

Ann Johnson has been a freelance writer since 1995. She previously served as the editor of a community magazine in Southern California and was also an active real-estate agent, specializing in commercial and residential properties. She has a Bachelor of Arts in communications from California State University, Fullerton.