Mechanical Pencils
Among the group of pencils, one of the items is the mechanical pencils. They are writing stationeries wherein the solid marking core is not bonded to the outer casing. Its core (writing tip) is generally made of graphite or lead.
Mechanical pencils are mainly used where there is need of lines with constant thickness and in between there is no need to sharpen them. This is the reason they are mainly used for technical drawings. These pencils generally look like ball point pens, but with a difference in writing tip. You can open it like a normal pen. However, you don't need to fill it with new ink cartridge; instead a long pencil lead refill is fed to the writing barrel.
