Mechanical pencil

A mechanical pencil or clutch pencil is a pencil with a replaceable and mechanically extendable solid pigment core called a "pencil lead", which is often made of graphite and not bonded to the outer casing, thus the user can mechanically extend it, as it is worn away from use. Mechanical pencils often include erasers. Mechanical pencils were first used in the 18th century. The first mass-produced mechanical pencil, the Eversharp, was patented in 1913 by Charles R. Keeran