Choosing the Right Micrometer

A micrometer is a measuring instrument used to measure small parts with extreme precision, usually to the thousandth or hundredth of a millimeter (0.001 or 0.01 mm, respectively).

It is used when manufacturing mechanical parts, in metrology, and in various industries that require the measurement of precise dimensions. Its use is crucial to guarantee the quality and conformity of the products manufactured.

Most analog micrometers have a metal arc with an anvil and a spindle. With each turn of the drum, the spindle moves forward or backward one step.

In addition to their measuring function, digital micrometers offer the possibility of comparing different dimensions with great precision.

View our micrometers

  • What are the criteria for choosing a micrometer?

    These are the main criteria to consider when choosing a micrometer:

    Type of micrometer

    There are different types of micrometers. Your choice will depend on your intended use:

    • An outside micrometer is used to measure the outside dimensions of an object.
    • An inside micrometer is used to measure the inside dimensions.
    • A depth micrometer is used to measure grooves and holes, even the deepest ones.

    Measuring range

    The measuring range of micrometers can be from a few millimeters to several centimeters, depending on the model. Make sure you choose a micrometer that is suitable for the dimensions of the parts you need to measure.

    Precision and resolution

    The accuracy and resolution of the micrometer are two fundamental characteristics. Precision corresponds to the degree of accuracy with which the micrometer can take measurements and depends on the quality of the instrument’s manufacture. Resolution, also called graduation, is expressed in micrometers (or microns) and indicates the smallest variation the instrument can measure. The resolution of the micrometer directly influences its accuracy. In other words, the higher the resolution, the more accurate the measurements.

    Measuring system

    Micrometers can have scales in millimeters or inches, depending on the country.


    On certain micrometers, it is possible to manually adjust the zero point to compensate for wear or to calibrate the device.


    The most common micrometers are vernier-type, using a fixed scale and a sliding scale. The most modern models have digital displays, which allow for a more accurate and faster reading.


    Ease of use and user comfort in cases of frequent use are important factors to consider when choosing a micrometer.


    The price of micrometers varies according to the quality and characteristics of the device.

  • What are the different types of micrometers?

    There are three main types of micrometers, each with different applications.

    STARRETT outside micrometer
    STARRETT outside micrometer

    Outside micrometers

    As the name suggests, these are used to measure the outside dimensions of an object, such as its length, width, thickness, or external diameter. They consist of an anvil (fixed) and a spindle (movable), which adjusts around the part to be measured.

    MITUTOYO inside micrometer
    MITUTOYO inside micrometer

    Inside micrometers

    These are used to measure the inside dimensions of a part, such as the diameter of a hole. There are internal two-point micrometers, three-point micrometers, and other caliper-type micrometers, with two movable points that move closer and further apart to adjust to the part being measured.

    MICROTECH depth micrometer
    MICROTECH depth micrometer

    Depth micrometers

    These are used to measure the depth of a hole, groove, or notch.

    They have a rod that is inserted into the workpiece to measure the depth precisely.

  • Digital or analog micrometer?

    Micrometers can be digital or analog. The choice depends on the user’s preference, the intended applications, and the precision required for the job. Digital micrometers have the advantages of precision and ease of use, while analog micrometers stand out for their durability and low cost. Some professionals work with both, using one or the other according to the measurement needs in each case.

    Below are the main advantages of each.

    TESA digital outside micrometer
    TESA digital outside micrometer

    Digital micrometers

    These micrometers have a digital display, which shows the measurements with great precision and makes them easy to read.

    They are recommended for jobs where quick measurement readings are required.


    • They take precise measurements with a resolution of up to one-tenth of a micrometer (0.0001 mm).
    • The digital screen makes it easier to read the results and reduces the risk of reading errors due to human factors, particularly parallax errors, which are more likely to occur with analog micrometers.
    • Some digital micrometers allow you to easily switch between units of measurement, i.e. between millimeters and inches.
    • Some models have a memory for storing a certain number of measurements, which can be useful for monitoring data or preparing reports.
    • There are also micrometers with advanced functions, such as tolerance and automatic zero.
    • Digital screens are generally backlit and offer good contrast, allowing you to read the results even in difficult lighting conditions and with vibrations.
    BOCCHI analog outside micrometer
    BOCCHI analog outside micrometer

    Analog micrometers


    • These are robust and resistant to impacts, vibrations, and, in general, extreme conditions in industrial environments.
    • Their price is lower than that of digital models, which may be a determining factor for some users.
    • They don’t need batteries to work.
    • They allow continuous reading.
    • Due to their simple mechanical construction, they generally require less maintenance than digital micrometers.
  • When should you choose an optical micrometer?

    MICRO-EPSILON optical micrometer
    MICRO-EPSILON optical micrometer

    An optical micrometer operates similarly to the previous types, except that it measures without physical contact with the object, which is placed between the emitter of the light beam and the receiver. It is a non-intrusive method that allows high-precision measurements to be taken without the risk of damaging fragile objects.

    An optical micrometer is a good choice for applications where extremely precise measurements are required, as detailed below. We also mention some of their main applications.

    High precision

    Optical micrometers make it possible to take measurements with a resolution/gradation of a few micrometers (or less than one micrometer, for devices intended for sub-micrometer measurements).


    • Research
    • Engineering
    • Manufacturing
    • Nanotechnology
    • Microelectronics
    • Cell biology
    • Surface inspection

    Optical micrometers are very useful for inspecting surfaces in detail to detect and measure roughness, defects, scratches, etc.

  • What other types of micrometers are there?

    Ball end micrometers

    These have one or two spherical tips, a feature that makes them suitable for measuring the distance between a hole and the edge of a part, but also for taking precise measurements on curved or irregular surfaces, for example in metrology activities.

    Blade micrometers

    These are suitable for measuring grooves and special shapes. It is advisable to use them when you need to measure parts with complex contours with great precision.

    Tube micrometers

    These have a long anvil that forms a 90º angle to the micrometer spindle. They are used to measure the thickness of pipe walls. They take fast and highly accurate measurements.

1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 1.00 out of 5)
No comment

Leave a Reply

Your email address will not be published. Required fields are marked *