All about mechanical pencils

Fun facts

The first mechanical pencil was found aboard the wreckage of HMS Pandora which was sank in 1791, and the first patent for a refillable pencil with lead-propelling mechanism was issued to Sampson Mordan and John Issac Hawkins in Britain in 1822.

Introduction

Mechanical pencils are rapidly replacing traditional wooden pencils, and there are hundreds and thousands of mechanical pencils to choose from. But what is a mechanical pencil? By definition, a pencil with a replaceable and mechanically extendable solid pigment core called a “lead” count as a mechanical pencil. The lead, which often made of graphite, is not bonded to the outer casing, and the user can mechanically extend it as its point is worn away from use.

Some benefits of using mechanical pencils include:

1. write and draw continuously without the need to sharpen
2. draw more precise and uniform lines, which is useful for technical drawing and writing
3. don’t need to throw away pencils, just refill, more environmentally friendly
4. more ergonomic for long period of use, but putting too much force on it can cause lead to break
5. they just look better

Lead

We can’t talk about mechanical pencils without mentioning the core of them - lead. Nowadays, pencil lead is made from a mixture of graphite and clay. The graphite is what makes the mark on the paper, while the clay keeps the graphite from being too soft and crumbly. The most commonly used sizes are 0.5mm and 0.7mm, both of these provide a favorable balance between precision and strength. 0.3mm is much thinner, so it is more technical and used more often in drawing and sketching. Most mechanical pencils can use only one single lead diameter. 

Comparison of popular mechanical pencils