Label the Parts of a Dial Caliper

One dial caliper face-on, nine numbers on it, to label on paper or on screen.

Label the Parts of a Dial Caliper

Name Date

Numbered worksheet

1 2 3 4 5 6 7 8 9
More options

Write the name of each numbered part.Answer key

  1. Outside jaws
  2. Inside jaws
  3. Beam
  4. Slider
  5. Dial
  6. Main scale
  7. Depth rod
  8. Locking screw
  9. Thumb roller

Drawn for this site by script, 2026-09-26. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

Next step The labeled dial caliper, and what each part does

All 9 parts on the diagram

Show the list

Start here: 6 main parts 6

  1. Outside jaws Close on the outside of an object to measure its width.
  2. Inside jaws Open inside a hole to measure its inside size.
  3. Beam The long bar the slider runs along.
  4. Slider Carries the moving jaws, the dial and the lock.
  5. Dial Shows the fraction of a millimetre or inch past the main scale.
  6. Main scale The graduations along the beam, read first.

Depth rod, lock and roller 3

  1. Depth rod Slides out of the end of the beam to measure depths.
  2. Locking screw Locks the slider so a size can be held.
  3. Thumb roller Rolled with the thumb to move the slider finely.

How this list was compiled: Read 2026-09-26. (1) Wikipedia, Calipers, https://en.wikipedia.org/wiki/Calipers : outside large jaws, inside small jaws, depth probe or depth rod, main scale, the retainer (lock), a fixed jaw and another jaw that slides along the scale, the beam, a wheel on some calipers; the dial caliper's rack and pinion turns a pointer on a round dial; its slide can be locked with a small lever or screw. (2) Mitutoyo, Quick Guide to Precision Measuring Instruments, Calipers: Nomenclature, https://www2.mitutoyo.co.jp/eng/pdf/E4329_QuickGuide.pdf : outside jaws, inside jaws, depth bar, beam, slider, locking screw, thumbwheel (thumb-roller), main scale, dial. Licence: own work

The drawing: Drawn for this site by script, 2026-09-26. Own work, nothing traced. Licence: own work

How it works

Label the parts of a dial caliper by number. 1 to 6 are the main parts, from the two pairs of jaws to the scale along the bar; 7, 8 and 9 are a rod, a screw and a wheel.

Read the full guide

Dial caliper word bank

In alphabetical order: beam, depth rod, dial, inside jaws, locking screw, main scale, outside jaws, slider, thumb roller.

Numbers that get swapped

At the left end, 1 is the pair of large jaws hanging below the bar (outside jaws), 2 the pair of small pointed ones above it (inside jaws). 3 is the long bar (beam), 6 the row of marks along it (main scale). 4 is the block that rides on the bar (slider), 5 the round face on that block (dial). Two small parts sit on the block: 8 is the screw on top (locking screw), 9 the wheel underneath (thumb roller). 7 is the thin rod at the far right (depth rod).

  • When marking, depth bar or depth probe is right on line 7, and thumbwheel on line 9.
  • The pointer on the dial and the marks along the bar are drawn without figures, so there is nothing to read off.

Questions and answers

Which jaw of a dial caliper moves?

One jaw of each pair is fixed, at the end of the beam. The other belongs to the slider and travels along the scale with it. The depth rod is attached to the slider too.

What does one turn of the dial on a caliper measure?

Typically one inch, a tenth of an inch or one millimeter: the pointer goes round once for each. That reading is added to the whole inches or centimeters read from the main scale.

Why can the dial on a caliper be turned?

The dial is usually made to rotate beneath the pointer, so it can be set to zero at any point. The caliper then shows the difference in size between two objects.

Is it caliper or calipers?

Both. One tool may be called a caliper or, like scissors, calipers. Caliper is the American spelling and calliper, with a double l, the British one.

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