For accurate measurements, a regular ruler is not enough. Used by most home craftsmen, it also does not always provide the necessary accuracy. If you need to measure a value such as a micron (μm), or 0.001 mm, you need a micrometer (in the illustration on the left).
Types of micrometers intended for professional and amateur use
According to the indication method, devices are divided into the following types:
Mechanical analogue, with static measurement scale
Readings are taken by aligning the marks on the scale. The handle with the micrometer screw is rotated until it touches the object, and the true size is calculated from the combination of numbers on the scale.
Measuring with this type of micrometer requires some skill.
Mechanical analog, lever
The operating principle is the same as the previous model - but it is much more convenient to use. The value of the measured quantity is displayed on a dial indicator. This is useful when mass measurements are being made.
Mechanical digital
Measurements are made using the same micrometer screw, but the readings are displayed on a liquid crystal display in real time. For this purpose, a precise displacement sensor is built into the mechanism.
Laser micrometers
Measurements are made using the laser beam intersection method. With the help of optics, the beam turns into a plane. The receiving photocell analyzes the decrease in beam width and displays the data.
The advantage of the device is the ability to measure products of complex shapes and the absence of mechanical contact with the measuring tips.
Disadvantages: inability to measure internal size. And of course, the cost. Not every home craftsman can afford such a tool.
According to the area of application, micrometers are divided into the following types:
The need to determine the linear dimensions of parts arises quite often. At the same time, the use of calipers and stationery rulers cannot be called an effective option for measuring with the required accuracy. To fully realize the tasks at hand, it is useful to learn how to use a micrometer.
Design
A standard hand-held micrometer consists of the following elements:
Features of operation
How to use a micrometer correctly? During measurements, the part is placed between the fixed heel of the device, after which it is secured with a screw that rotates in a threaded sleeve. A rigidly fixed drum facilitates unscrewing the screw.
When learning how to use a micrometer, special attention should be paid to the tightening force of the screw. Exceeding the permissible limit can lead to damage to the thread of the device or deformation of the measured object.
How to use a micrometer - instructions
Before each use of the device, it requires calibration, since the measuring scale gets lost as it is used. To do this, the screw is screwed in until it stops. The correct setting is when the horizontal mark on the stem of the structure coincides with the zero value on the drum. If there are deviations, the stem is twisted using a special key, which should come with the device.
To figure out how to use a micrometer, you first need to adjust the bracket so that the part being measured fits freely between its planes. You can adjust the device by rotating the drum. Next, the part to be measured is installed between the fixed stop and the screw. The latter is fixed with a ratchet and tightened with a ring nut.
The required dimensions are determined by combining the readings of the three scales of the device. The upper part of the scale located on the stem of the device allows you to determine the number of full millimeters. If on the lower scale the last division gravitates towards the right side, 0.5 mm is added to the resulting measurement. Finally, the drum scale indicator is added to this result, where the value of one division is 0.01 mm.
Storage and care
Obviously, understanding how to use a micrometer is not at all difficult. However, regardless of the nature of the measurements, the device must always be in full readiness to perform new measurements. Therefore, it is extremely important to keep it in good functional condition.
After use, the micrometer needs to be cleaned from dust and contaminants, because quite often measurements must be taken in rooms that can hardly be called sterile. Measuring surfaces require especially thorough cleaning. To obtain accurate readings, the user must ensure that they are kept smooth and in their original shape. To do this, when caring for the device, you should avoid using abrasives.
It is better to store and carry the micrometer in a special case, which will avoid damage if accidentally dropped. Some models are supplied complete with a protective case. If necessary, you should definitely purchase it.
Today you can buy a micrometer at any instrument store. Such a convenient device will become indispensable both in production and in the home, for example, if it is necessary to measure the thickness of wiring.
There are times when it is necessary to accurately measure a small part: a cut from a wire, or, for example, the diameter of a drill. A regular ruler or caliper will not work here. In this case, a micrometer is used to take measurements. The device allows you to determine the size of a part with an accuracy of a thousandth of a millimeter. And if calipers are familiar to many craftsmen, not everyone knows how to use a micrometer, the instructions for use of which are not always clear. The device will be useful for both a novice craftsman and an experienced carpenter. Today in our site review we will tell you what a micrometer measures, how to work with it, and also get acquainted with the purpose of the devices for different purposes.
Read in the article:
Micrometer - what is it: a little about the history of the device
The operation of the device is based on a simple but effective mechanism - a screw pair. All measurements are carried out using the contact method. The part is clamped with a vice, and the rotated screw in the nut, the pitch width of which varies depending on the type of device, moves along the axis.
Important! The length of the working screw is usually no more than 25 mm, and micrometers are produced in various standard sizes corresponding to the range of measured lengths.
By the way, a screw pair for precise sizing was used back in the sixteenth century. In those distant times, it was included in the design of sights for guns, as well as geodetic instruments. The patent for the micrometer was received by the Frenchman Palmer in 1848. But it was not widely used. Only 19 years later, American engineers Lusnan Sharpe and Joseph Brown paid attention to the device and organized mass production of micrometers.
How does a micrometer work and what does it consist of?
The device of a micrometer is very simple. All micrometer mechanisms are located on the bracket (5), and the heel (2) is attached to it. It acts as a stop during measurements. At the opposite end of the bracket, the stem (3) is rigidly fixed; it is a hollow cylinder. A scale is marked on the stem; its division is usually 0.5 mm. Inside the stem there is a screw pair and a fastening mechanism (6). The smooth part of the micrometer screw extends from the stem into the measuring area and ends in a flat measuring surface. The opposite part of the micrometer screw is rigidly connected to the drum (4). The drum has a scale that allows you to count hundredths or thousandths of a millimeter.
Important! For household measurements, micrometers are most often used, the unit of measurement of which on the drum is 0.01 mm.
A ratchet (7) is located at the outer end of the drum. It limits the torque applied by the human hand when rotating the screw, which helps avoid deformation of the part during measurements. The ratchet is also used during the preliminary adjustment of the element (we will talk about this in more detail below).
Working principle of a micrometer
Micrometers may differ slightly in design, but the principle of operation is the same - the part is placed between the stationary heel of the device, after which it is secured with a screw that rotates in a threaded bushing.
When the device is firmly fixed, you will hear a corresponding click of the drum. Now you need to take measurements. As we have already found out, the micrometer has two scales - a fixed one on the stem (in mechanical structures, the division value is usually 1 mm), then we look at the data on the rotating drum scale (these divisions show fractions of a millimeter). There are 50 divisions on the drum, the microscrew pitch is 0.5 mm. A full revolution of the drum gives us a movement of the microscrew by 0.5 mm. Thus, by adding the dimensions from two scales, we obtain the exact size of the part.
Important! When working with the tool, special attention should be paid to the tightening force of the screw. Exceeding the permissible limit can lead to damage to the thread of the device or deformation of the measured object.
Types of micrometers
Let's consider the types of micrometers intended for both professional and domestic purposes.
According to display option
Based on the method of taking measurements, several types of micrometers can be distinguished, each of which has its own pros and cons.
Mechanical analogue, with static measurement scale
This is exactly the kind of device that can be found in an ordinary workshop.
For measurements, the part is placed in a measuring vice. The handle with the micrometer screw is rotated until it touches the part, then the mater takes readings according to the marks on the scales.
A huge advantage of a mechanical device is that it is not afraid of falls. After such an emergency, you only need to reconfigure the device. The downside is the relatively large measurement step.
Mechanical analog, lever
The operating principle is the same as the previous model - but it is much more convenient to use. The value of the measured quantity is displayed on a dial indicator. This is useful when mass measurements are being made.
Mechanical digital
Measurements are made using the same micrometer screw, but the readings are displayed on a liquid crystal display in real time. For this purpose, a precise displacement sensor is built into the mechanism.
Laser micrometers
Measurements are made using the laser beam intersection method. With the help of optics, the beam turns into a plane. The receiving photocell analyzes the decrease in beam width and displays the data.
The advantages of such micrometers are undeniable:
- High accuracy.
- The division value is 0.001 mm.
- Fast measurements.
- In any position from the measurement range, you can set the zero value.
- You can measure a part with a complex shape.
However, there are also significant disadvantages:
- Mechanical vulnerability.
- Does not measure internal size.
- High price.
By area of application
Micrometers are used to control accuracy in many areas. There are several types of devices, depending on the area of application.
Smooth micrometer
This is one of the most commonly found devices. They measure flat and round surfaces - the dimensions of parts and sections.
Micrometer - toothometer
Determines the linear dimensions of gear teeth and gears. Has special conical nozzles. As a rule, the kit includes a standard length measure.
Pipe micrometer
They measure the thickness of walls in pipes. It is used at the stage of checking production quality, as well as wall wear. Moreover, special attachments help measure the thickness of even curved and uneven sides. The probe touches the wall pointwise due to its shape.
Sheet micrometer
Allows you to accurately measure the thickness of sheet, film and roll products. The feed screw is set to a small scale range, so the measurement accuracy is very high.
There are two types of such devices:
- With flat nozzles, for measuring narrow workpieces.
- With extended jaws– for taking measurements of large area products, at a distance from the edge.
Universal micrometer
The ability to change heads allows you to measure a wide variety of parts. However, due to the extra connecting nodes, the instrument error suffers.
Wire micrometer
A highly specialized device used to measure the diameter of wire and balls in bearings. Due to this, the design is more compact.
Prismatic micrometer
Used to measure the diameter of a multi-blade tool. The support is made in the form of a prism.
Groove micrometer
Sometimes you can come across another name - depth gauge. With its help it is easy to measure the depth of recesses, grooves, defects in relation to the reference plane. The micrometer is mounted on the surface using a base plate, and the depth is measured using a probe.
Thread micrometer
The scale can be either metric or inch. The kit includes special attachments for various types of threads.
Dual scale micrometer
Sets the maximum external dimensions of one workpiece. Used to calculate dimensions.
Micrometer for hot rolling
With its help, you can measure the thickness of the product directly during production. A special calibrated wheel is used as a meter.
Micrometer - bore gauge
Helps measure internal diameters of products. Used to control the quality of manufacturing parts.
Let us add that each group has its own pros and cons. For example, even a laser micrometer purchased from an unknown manufacturer can give false readings. When purchasing, be sure to check the accuracy of the device.
How to Adjust a Micrometer and Check Calibration Accuracy
During operation, the micrometer scale periodically gets lost. Therefore, it is advisable to calibrate the device before each use. To do this, you need to completely tighten the screw and see if the zero mark on the drum coincides with the horizontal mark on the stem. If necessary, you can repair the micrometer yourself.
To check the measurement accuracy of a micrometer with a measurement range of 25 - 50 mm, 50 - 75 mm and more, corresponding standards (gauge gauges) are used, the size of which is known to hundredths of a millimeter. The standard, which has a clean end surface, must be clamped without distortions between the measuring surfaces of the device using a ratchet force of several clicks. The obtained value is compared with the known one, and if necessary, the micrometer is adjusted.
Setting the micrometer to zero
Let us consider in detail how to adjust the micrometer to the zero mark, with a working range of 0-25:
| Illustration | Description of action |
 | Before selecting the gap to zero, it is necessary to clean the working surface of the heel and screw jaws. To do this, unscrew the screw a little, take a piece of glossy paper (a fragment of a magazine cover or postcard will do). We clamp the fastener together with it and pull out the piece of paper. This way we will clean our working tools from possible dust, debris and dirt. |
 | We bring the heel and the screw together and tighten the fixing screw. This is necessary in order to fix our device at the zero mark in the future. |
 | Using a special wrench, loosen the drum and remove it. Our task is to return the drum to the position that would correspond to the zero mark. |
 | For precise adjustment, the end of the drum must stop clearly at the zero mark of the stem. And the zero mark of the drum scale should stop opposite the longitudinal stroke. |
How to measure with a micrometer
Working with a micrometer requires high precision and accuracy. Before starting measurements, let us once again recall the main points of handling the device.
Basic rules for using a micrometer
A micrometer, like any other device, requires careful and correct handling. To improve the measurement accuracy of the device, the following points must be taken into account.
- If the device has a holder, which is most often attached to a bracket, it must be firmly fixed.
- Be sure to wipe (this has been discussed more than once today) the surface of the heel and screw jaws.
- Zero readings are verified. If the display is incorrect, this device must be reconfigured.
- Do not use excessive force when fixing a part with a ratchet! The surface of the clamping mechanisms is made of high-strength materials, so if pressed excessively, they can damage the part being measured.
- It is better to store the micrometer in a special case or bag.
How to measure with a micrometer correctly
Let's look at an example of how to use a micrometer:
| Illustration | Description of action |
 | To control measurements we use fishing line. The manufacturer claims a thickness of 0.28 mm. |
 | Before starting the measuring process, you should unscrew the screw so that the distance is slightly larger than the fishing line by rotating the drum. In this case, you should not use a ratchet! The fishing line may simply be flattened. |
 | Using the upper part of the stem scale, we determine the number of full mm. Moreover, if on the lower half the last visible mark is to the right, then we add another 0.5 to the resulting value (this is why the lower half of the scale is offset relative to the upper). |
 | As we see, the manufacturer cheated with the data. The line exceeds the declared value by 0.02 mm. Total diameter 0.30 mm. Do not forget that for correct calculation, to the number shown by the cylinder, we add the value from the drum scale, the division value of which is 0.01 mm. |
How much does a micrometer cost: review of popular models and prices
Today you can buy a micrometer at any instrument store. Such a convenient device will become indispensable both in production and in the home, for example, if it is necessary to measure the thickness of wiring.
| Name | Manufacturer | a brief description of | Price (as of May 2018), rub. |
| Matrix (Germany-China) | The micrometer is made of tool steel. It has the shape of a staple. The main working element is the micrometer head. Packed in a plastic case. | 700 |
| Zubr OVK (Russia) | Mechanical smooth micrometer Measurement step 0.01mm | 800 |
| Norgau (Russia-China) | Stem and drum with matte chrome plated. Measuring spindle Ø 6.35 mm, spindle movement 0.5 mm/revolution; With clamping screw and ratchet; Measuring surfaces are carbide, ground, finely lapped; The bracket is covered with enamel; The housing of the NORGAU micrometer is made of durable steel. | 2300 |
| Zubr OVK (Russia) | Smooth Digital Micrometer Measuring range 0 – 25 mm. Measurement step 0.001 mm. | 3969 |
| Schut (Norway-Taiwan) | Smooth micrometer Measuring range 50-75 mm. The surface is made of ultra-strong alloys | 13400 |
| Calibron (Russia) | Smooth electronic micrometer MKTs 50-75. Measurement step – 0.001 mm. Designed to measure the external dimensions of products. The micrometers are equipped with an electronic digital reading device, the error is 0 | 10000 |
Smooth micrometer 
At the end of the article, we invite you to watch a video tutorial on how to use a micrometer.
In one of my previous videos, I showed a device for measuring dimensions called a caliper. A caliper is the simplest device, but it allows you to measure dimensions with very high accuracy, specifically my device allows you to measure dimensions with an accuracy of 5 hundredths of a millimeter, and there are devices that allow you to measure dimensions with an accuracy of 2 hundredths of a millimeter. In this video I will also talk about a device for measuring dimensions, only about a device of a slightly different class.
This is a micrometer. This particular device allows you to measure dimensions with an accuracy of 1 thousandth of a millimeter. There are simpler micrometers that look about the same, but have an accuracy of one hundredth of a millimeter. This is very high accuracy.
I’ll tell you about the task that a micrometer can brilliantly handle a little later, but for now I’ll show you how to use a micrometer and how to measure with it. The micrometer has jaws (“1”). When we turn the screw marked “2” in the photo, the jaws converge or diverge. Measuring with this device is very simple, just take the object that you want to measure, hold it in the jaws, and rotating this disk, clamp the object to a certain force. Let's say you have placed some kind of part to be measured, and with what force should you clamp it? This raises a very reasonable question, because if the part is made of a soft alloy, such as aluminum or copper, then pressing this part will flatten it, and you will measure the flattened part. It will cost you a couple of hundred, and the data will no longer be reliable. If you take a drill or other carbide part, then pressing harder, you can break the threads in the device and ruin it. You need to clamp to a certain limit. This limit is indicated differently for different micrometers. Specifically, the device that I now have in my hands is equipped with a scale that has two red frames. These frames set the limit within which the required clamping force of the jaws is ensured. That is, if the arrow of the device is not between the two red arrows, it means either it was not clamped enough (the arrow of the device is at the beginning of the scale), or it was too tight (the arrow of the device is at the end of the scale). In the photo, the micrometer arrow is between the two red arrows, which means that the part being measured has been pressed with the required force. 
Other devices use a ratchet disc. That is, a small disc handle has been added to the main handle, on which there is a ratchet. That is, when you clamp the jaws, you no longer rotate the main handle, but begin to rotate the second handle with the ratchet. And as soon as you clamp to the required force, the ratchet begins to slip and will not allow you to clamp the part harder than necessary, and you will hear the ratchet crack, which means that everything is fine and it’s time to read the readings.
How to read readings from a micrometer? In order to take readings, you need to lock the scale so that it does not move; to do this, you need to tighten the nut (1). If I want, I can, of course, twist it, but I can’t easily move it by accident. This device has such an awesome little thing, like this button (2), which slightly moves the thrust part (3), which allows you to remove the part being measured, all this is clearly demonstrated in the video clip about the micrometer. 
Reading the micrometer scale couldn't be easier. The device has two scales. One is on the disk (“1”), and the second is on a fixed chassis (“2”). The scale is on a fixed chassis, divided into two subscales. They are both marked in mm, but there is a slight difference in that the lower scale is shifted relative to the upper one exactly half a mm to the right. That is, the first little mark on the lower scale is exactly halfway between zero and one mm. Now you will understand why exactly half a mm. 
Next, the micrometer has a disk that has exactly 50 lines, each of which is marked in hundredths of mm. One full revolution of this disk moves the micrometer jaws exactly half a mm. That is why the lower scale is shifted by half a mm to make it easier to count. 
Let's try to take the readings obtained when measuring with a micrometer in the figure above. We get a full 4 mm, and a little more. We see that we have selected the lower risk, which adds another half mm, or 50 acres, to 4 mm. To these 50 hundredths you need to add the value that is now on the disk; on the disk it is also in hundredths. Now we have 29. That is, it turns out 4 mm, 50 hundredths, plus 29 hundredths. Total 4.79 hundredths of mm. 
Let's spin the micrometer disk a little more and count how much we get in the figure above. It turns out to be a full 6 mm, and a little mark has appeared on the lower scale, which means that another 50 hundredths of a mm needs to be added to these 6 mm. We get 6 whole and 50 hundredths, and a little more, which we read from the disk. On the disk the value is 3, which means 3 hundredths of a mm. Total 6 whole and 53 hundredths mm.
This micrometer has one feature that most instruments do not have. This is a scale that allows you to measure dimensions with an accuracy of one thousandth of a mm. It, in turn, serves as an indicator for sufficient support, or clamping. On this scale, 10 pictures are equal to one picture on the disk, or one hundredth. Now the device shows 0. Now I will move the dial exactly one division, and you will see that the arrow will move to the value 10. 
I'll try to measure the toothpick with a micrometer. I install and tighten until the arrow hits the limit beyond 0 to the right. Then I twist it until we have one picture on the disk that matches. You just need to tighten it up, because it’s easier to count. You can, of course, unscrew it back, but then you have to subtract. So I twisted it so that my risk exactly matches. I tighten the lock nut and read the reading. I get 2 whole and 5 hundredths and I need to add another 10 thousandths, which is on the thousandths scale, that is, 1 more hundredth. I get it, 2.05 + 0.01 = 2.06mm. Now I have this size 2 and 6 hundredths mm. 2 comma, 0 6. 
For example, you can hold a micrometer like this: take the device, take the part, somehow hold it with your other hand as follows... and clamp the disk. If we need the next measurement, we release it, place the drill, take the next part, hold it again and clamp it again. In my opinion, holding a micrometer this way is wrong. 
In my opinion, this is very inconvenient, and there is the following way to hold the micrometer correctly:
To do this, take the device as follows: insert 2 fingers and hold it in your hand. At the same time, our second hand is absolutely free, and we can take parts even half a meter from the place where you measure. Using the fingers of the hand in which the micrometer is located, you can freely rotate the disk. 
This way, in my opinion, it is much more convenient to work. You need to measure something, you took it, tried it on, released it, took another part. In this case, your hand with the micrometer is on the table, that is, in a non-suspended state. You make fewer movements, therefore you get tired less, stress less, and your work progresses much more interestingly. Therefore, hold the device as in the picture above.
I also really like this micrometer because it has a button that releases the part being clamped. How is this convenient? Well, firstly, it is convenient to select several identical products, say, with a tolerance of 10 thousandths. We install the reference part and set the arrow on the thousandths scale to zero. Let's counter the scale. We put the next part and look at the thousandths scale.
The second thing that makes this button convenient is that you can measure the thickness over the entire plane of the product, which should have the same size over the entire plane. Naturally, it will not be the same, there is always a tolerance, these are some hundredths, thousandths. We fix the size at the first point. We bring the arrow of the thousandths scale to 0, and lock the nut. By pressing the button, we release the part and transfer it with another part into the jaws.
As I already said, in amateur radio practice there is a task that only a micrometer can cope with amazingly well. This, as you probably already guessed, is measuring the diameters of the winding wires.
OK it's all over Now. Here is such an interesting little device, a micrometer, which is very necessary for determining the diameters of wires, because you often use used wire that you unwind from other transformers, and you need to know its diameter. But to be honest, you rarely need a micrometer, and for a short time. You can take it, measure all the wires you have in your household, and give it back again. It won't be needed again in the next six months.
From time to time there is a need to accurately determine the linear size of a part. At the same time, a stationery ruler and calipers are not always able to provide the required accuracy class. In this situation, a micrometer should be used.
Micrometer structure: 1 – heel, 2 – screw, 3 – ring nut, 4 – fixed stem, 5 – drum, 6 – ratchet.
A micrometer is a universal tool that allows you to determine the external size of a part with an accuracy of 2 microns (1 micron = 0.001 mm). According to the type of execution, they are divided into mechanical and electronic. We will look at how to use a micrometer using the mechanical version as an example. Due to the design feature, namely the difficulty of manufacturing a micrometer screw with a length of more than 25 mm while maintaining pitch accuracy, several standard sizes of the device are produced.
In a micrometer, the part to be measured is clamped between a fixed stop (heel) (1) and a micrometer screw (2), rotating in a threaded bushing of a fixed stem (4). The screw is unscrewed using a drum (5) rigidly fixed to it.
To avoid the possibility of damage to the object being measured or the thread of the device when the screw is over-tightened, it should be tightened using a ratchet (6).
The screw can be fixed in any position with a ring nut (3).
The instrument has 2 scales. The first, with a division value of 1 mm, is located on the stem. In turn, it is divided into 2 parts, with the lower one displaced relative to the upper one by 0.5 mm. This is done to make the measurement process easier. The second scale is located on a rotating drum. It has 50 divisions with a value of 0.01 mm.
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Using a micrometer
The micrometer has 2 scales - 1 is on the stem, and the other is on the drum.
Using the tool is extremely simple, there is no need for detailed instructions, the main thing is to see once how to use a micrometer, and everything will immediately become extremely clear. In order to learn how to use a micrometer correctly, we will consider the measurement process first theoretically and then using specific examples.
During operation, the scale periodically gets lost. Therefore, before each use of the micrometer, it is advisable to calibrate the device. To do this, you need to completely tighten the screw and see if the zero mark on the drum coincides with the horizontal mark on the stem. If these marks do not match, then you should twist the stem using a special key that is included in the kit.
Before starting the measurement process, you should unscrew the screw to a size slightly larger than the part being measured by rotating the drum. Then place this part between the screw and the fixed stop, tighten it with a ratchet until it makes a characteristic sound and tighten the ring nut.
To determine the size, you need to add up the readings of 3 scales (2 on the stem and one on the drum). Using the upper part of the stem scale, we determine the number of full mm. Moreover, if on the lower half the last visible mark is to the right, then we add another 0.5 to the resulting value (this is why the lower half of the scale is offset relative to the upper). Next, we add the value from the drum scale, the division price of which is 0.01 mm.
