Parts of a Mechanical Pencil – Outside and Cut Open

All 10 parts on the diagram

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Outside 4

Barrel The body of the pencil. Everything else fits inside it or onto it.
Grip Where the fingers hold the pencil. Many are ribbed or made of rubber.
Clip It holds the pencil in a pocket.
Push button Pressing it feeds the lead forward a little at a time. The eraser sits under it.

Inside 6

Lead A thin stick of graphite mixed with clay or plastic. It contains no lead metal.
Lead sleeve It protects the lead from breaking. It lets the tip run along a ruler.
Chuck It clamps the lead for writing and lets go to feed it. Also called the clutch.
Spring It supports the mechanism. Some pencils have a second one that cushions the lead.
Lead tube It holds the spare leads. It is also called the lead reservoir.
Eraser Sits in the end of the lead tube, under the push button.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two independent sources use it. (1) A pencil maker's product information for mechanical pencils, 2002, with a labeled lengthwise section, full text at https://archive.org/details/generalmanual_000037889 (barrel, lead sleeve, clamping chuck, chuck ring, lead tube, lead retainer, springs, push-button). (2) Wikipedia, text only, Mechanical pencil, https://en.wikipedia.org/wiki/Mechanical_pencil (barrel, lead, eraser, lead sleeve, spring-loaded, clutch pencil). (3) Passages returned by the Internet Archive's full-text search from: an art magazine of September 1990, https://archive.org/details/sim_artists-magazine_1990-09_7_9 (grip, push-button, lead sleeve, eraser); a second maker's product catalog, https://archive.org/details/manualzilla-id-7157557 (rubber grip, pocket clip, eraser); an office magazine of June 1986, https://archive.org/details/sim_office_1986-06_103_6 (pocket clip, eraser); the Official Gazette of the United States Patent Office, https://archive.org/details/officialgazette1167aunit (lead holding chuck, lead reservoir); Consumer Reports, March 1938, https://archive.org/details/sim_consumer-reports_1938-03_3_3 (lead reservoir); and a collector's catalogue of American mechanical pencils, https://archive.org/details/catalogueofameri0000vele (clutch, button, cap, lead tube). Hints and detail lines are in our own words. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's pencil, nothing traced. Not to scale. Licence: own work

How it works

The parts of a mechanical pencil in two drawings. Four show from outside: barrel, grip, clip and push button. Six more sit inside, from the lead sleeve at the tip to the eraser under the button.

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Follow the lead from back to tip

Spare leads wait in the lead tube. One lead runs forward between the jaws of the chuck and out through the lead sleeve. Press the push button and the chuck moves forward, lets go, and takes a new hold farther back, so a little more lead shows. A spring supports the mechanism. The eraser sits in the end of the tube.

Lead sleeve and lead tube are easy to swap: the sleeve is the thin pipe at the tip, the tube is the store inside.
Chuck and clutch are two names for the same jaws.

Questions and answers

What is the tip of a mechanical pencil called?

The thin metal pipe the lead comes out through is the lead sleeve. It protects the lead from breaking and lets the tip follow a ruler or a template.

What holds the lead in a mechanical pencil?

The chuck, also called the clutch: jaws that clamp the lead so it cannot slip back while you write. Pressing the push button opens them for a moment to feed the lead.

Where do the spare leads go in a mechanical pencil?

In the lead tube, also called the lead reservoir, the inner tube that runs up the barrel. They are dropped in at the back end of the pencil.

Is there lead in mechanical pencil lead?

No. Pencil leads, also called cores, are usually made of graphite with clay or a plastic binder. They do not contain the metal lead.