What is the best mechanical pencil for drawing and writing? In this article, we review the 15 Best Mechanical Pencils 2020. Mechanical Pencils are pencil with a metal or plastic casing and a very thin replaceable lead. Most mechanical pencils have extended the lead as the point is worn away by twisting the outer casing. Mechanical pencils are often used by students and professionals in the engineering profession to provide lines of constant even width without sharpening in technical drawing and in quick, neat writing. They are also used in fine-art drawing.