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Micrometer Part Names: What Are The Parts Of A Micrometer?

A micrometer is an important tool in engineering that consists of several parts. I will be talking about the main parts of a micrometer in this article.

The main parts of a micrometer that I will be discussing below are:

  • The sleeve scale
  • The thimble scale
  • Fame
  • Spindle
  • Anvil
  • Lock
  • Ratchet
  • Measuring faces
  • Screw

What are the main parts of a micrometer

A normal mechanical micrometer has the below parts:


The main work of the Anvil is to hold the workpiece or object you are measuring its dimensions. Therefore, this part is stationary and connected to the mainframe.

The Anvil is one of the parts that distinguish between different micrometer types.
Depending on the use, you can get a micrometer that has a changeable anvil.
Therefore, you can replace the initial Anvil with a different type to suit your work.


The frame is a visible, U-shaped main part of the micrometer.
The frame represents a wide range of measurements.

When you have a larger frame, you will have a longer range or measurement, and vice versa is true.

Its main work is to offer support to the spindle and Anvil to have a better chance of securing the object you are measuring.

The frame is designed with a plastic coating to prevent your body heat from getting to the micrometer.


The spindle has the same work as the Anvil: holding the workpiece while measuring, but it is movable.
When you turn around the thimble scale, the anvil scale will also turn.

Axially, the Anvil will either move backward or forward to untighten or tighten the workpiece, depending on what you want.

The spindle is a long metal tube with threads half of its body.
Therefore, it is directly connected to the micrometer’s screw.


It holds several parts of the micrometer.
It is a barrel that allows the thimble scale to rotate and is responsible for the occurrence of the micrometer’s primary scale.

Depending on what you want and what you understand better when measuring objects, it can be in inches or millimeters scale.
This part is not moving.

Because of that, you can get an etched Vernier scale in some cases.
Also, you can find the index line is on the sleeve.


It is another important part that ensures you have the correct reading.
It works by preventing movements of the object when you are taking readings.

Any small movement while reading the micrometer can cause inaccuracy.
When you turn the lock, you make it hold the workpiece tighter.

It is visible as a nut lock.
However, they come in different types, some looking like a ring that you should rotate for it to work.

Regardless of the type of lock you have or want to buy, their work function is similar.


A rotatable cylinder at the end of this tool is called a ratchet.
The main function is to ensure that the workpiece is held with enough pressure.

If you apply too much pressure when tightening the object, you can break the device.
On the other hand, the reading will be inaccurate if the pressure is loose.

You will hear a click sound when you apply enough pressure to hold the object.
It is a safety part.


It is similar to the sleeve, but this barrel is movable.
The thimble is larger in diameter than the sleeve, hence rotating on top of it.

A secondary scale takes place here.
The main function of this part is to magnify the main scale’s resolution.
A single division on the main scale is divided into many divisions.

Measuring faces

These are parts that touch the surface of the workpiece you are measuring.
They are on the edge of the spindle and Anvil and are made of strong metal.

Initially, these parts were made of steel to empower their hardness.
Nowadays, carbide material is widely used to make the tip of the measuring faces.

If you set your micrometer to zero, the measuring faces will meet.


It is a critical part that determines the working condition of the micrometer.
You can find the screw inside the thimble barrel.

Therefore, you need to unassemble the whole micrometer to see its real shape.
You will realize that the screw is threaded to connect each other.

Micrometer part names: What are the parts of a Micrometer?

A micrometer comprises a few parts that ensure its proper function in measuring objects.
These parts are:

  • The sleeve scale
  • The thimble scale
  • Fame
  • Spindle
  • Anvil
  • Lock
  • Ratchet
  • Measuring faces
  • Screw