A
mechanical pencil (US English) or a
propelling pencil (UK English) is a
pencil with a replaceable and mechanically extendable solid pigment core called a "lead" . The lead, often made of
graphite, is not bonded to the outer casing, and can be mechanically extended as its point is worn away. Other names include
automatic pencil,
drafting pencil,
technical pencil,
click pencil,
clutch pencil,
leadholder,
pen pencil (Indian English),
lead pencil (Bangladeshi English), and
pacer (or
spacer).