Vernier calipers purpose and application. The device of various types of calipers

Determination of readings by vernier

To determine the readings of a caliper, it is necessary to add the values ​​of its main and auxiliary scales.

1. The number of whole millimeters is counted on the bar scale from left to right. The pointer is the zero stroke of the vernier.
2. To count fractions of a millimeter, it is necessary to find the vernier stroke that most accurately matches one of the strokes of the main scale. After this, you need to multiply the serial number of the found vernier stroke (not counting zero) by the value of its scale division.

The measurement result is equal to the sum of two quantities: the number of whole millimeters and fractions of mm. If the zero line of the vernier exactly coincides with one of the lines of the main scale, the resulting size is expressed as an integer.

The figure above shows the readings of the ShTs-1 caliper. In the first case they are: 3 + 0.3 = 3.3 mm, and in the second - 36 + 0.8 = 36.8 mm.

The instrument scale with a division value of 0.05 mm is presented below. For example, two different indications are given. The first is 6 mm + 0.45 mm = 6.45 mm, the second is 1 mm + 0.65 mm = 1.65 mm.

Similar to the first example, you need to find the strokes of the vernier and the rod that exactly match each other. In the figure they are highlighted in green and black, respectively.

Mechanical caliper device

The design of a double-sided caliper with a depth gauge is shown in the figure. The measurement range of this tool is 0-150 mm. With its help, you can measure both external and internal dimensions, the depth of holes with an accuracy of 0.05 mm.

Essential elements

1. Barbell.
2. Frame.
3. Sponges for external measurements.
4. Sponges for internal measurements.
5. Depth gauge ruler.
6. Locking screw for fixing the frame.
7. Vernier scale. Serves to count fractions of millimeters.
8. Bar scale.

The jaws for internal measurements 4 are knife-shaped. Thanks to this, the hole size is determined on a scale without additional calculations. If the caliper jaws are stepped, as in the ShTs-2 device, then when measuring grooves and holes, their total thickness must be added to the readings obtained.

The reading value of the vernier may differ for different instrument models. So, for example, for ShTs-1 it is 0.1 mm, for ShTs-II it is 0.05 or 0.1 mm, and the accuracy of devices with a vernier reading value of 0.02 mm approaches the accuracy of micrometers. Design differences in the design of calipers can be expressed in the shape of a moving frame, measurement ranges, for example: 0–125 mm, 0–500 mm, 500–1600 mm, 800–2000 mm, etc. The measurement accuracy depends on various factors: vernier reading values, work skills, good condition of the tool.

The procedure for carrying out measurements, checking serviceability

Check before work technical condition caliper and adjust it if necessary. If the device has warped jaws, it cannot be used. Nicks, corrosion and scratches on working surfaces are also not allowed. It is necessary that the ends of the rod and the depth gauge ruler coincide when the jaws are aligned. The instrument scale must be clean and easily readable.

Measurement

• The caliper jaws are pressed tightly against the part with little force, without gaps or distortions.
• When determining the outer diameter of a cylinder (shaft, bolt, etc.), make sure that the plane of the frame is perpendicular to its axis.
• When measuring cylindrical holes, the jaws of the caliper are placed at diametrically opposite points, which can be found by focusing on the maximum scale readings. In this case, the plane of the frame must pass through the axis of the hole, i.e. Measurement along the chord or at an angle to the axis is not allowed.
• To measure the depth of a hole, a rod is placed at its edge perpendicular to the surface of the part. The depth gauge ruler is pushed all the way to the bottom using a movable frame.
• The resulting size is fixed with a locking screw and the readings are determined.

When working with a caliper, monitor the smooth movement of the frame. It should sit tightly on the bar without swaying, while moving without jerking with moderate force, which is regulated by the locking screw. It is necessary that when the jaws are aligned, the zero stroke of the vernier coincides with the zero stroke of the rod. Otherwise, reinstallation of the vernier is required, for which the screws securing it to the frame are loosened, the strokes are aligned and the screws are re-fastened.

Vernier calipers are used to determine the outer and inner diameters, linear dimensions, depths of grooves and holes, as well as distances between ledges. Some modifications allow markings to be applied to the surfaces of workpieces. The tool is used to measure workpieces in mechanical and metalworking production areas, to control the production of wear surfaces when repairing equipment, and due to its ease of use, it is used in home workshops.

Shown in Fig. 1 caliper type ШЦ-1 consists of:

1. Barbells.
2. Framework.
3. Measuring scale.
4. Upper lips.
5. Lower lips.
6. Depth gauge.
7. Vernier scales.
8. Clamping screw.

The choice of caliper for a specific task is determined by the dimensions, design features of the part and requirements for dimensional accuracy. The tools differ in the following parameters:

• Measuring range. The length of the scale on the rod ranges from 125 to 4000 mm.
• Accuracy. Common modifications have an error of 0.1, 0.05, 0.02 and 0.01 mm.
• Functionality. There are calipers with and without a depth gauge.
• The number and shape of measuring surfaces. The jaws of single-ended and double-ended instruments are available in flat, pointed or rounded shapes.
• The design of the reading device. It can be vernier, mechanical, clock type or electronic.

Vernier calipers are made of wear-resistant tool steels, and their measuring surfaces can be reinforced with carbide tips. To mark parts, cutters are installed on non-sharpened jaws (Fig. 2), complete with holders and clamping screws.

Measurement order

The tool and part need to be prepared for work: remove dirt, bring the jaws together and make sure that the readings correspond to “0”. To measure the outer diameter or linear dimension you must:

• spread the sponges by moving the frame;
• move until it fits snugly against the countersurfaces;
• fix the position of the frame with a locking screw;
• bring out a caliper to evaluate the results obtained.

To measure the internal size, the jaws are brought to “0” and then moved apart until they come into contact with the countersurfaces. If design features details allow you to see the scale, then the readings are read without fixation and removal.

To measure hole depth:

• by moving the frame, the depth gauge is extended;
• lower it into the hole to the bottom and press it against the wall;
• move the bar until it stops at the end;
• fix with a locking screw and remove.

The accuracy of the results depends on the correct positioning of the jaws relative to the part. For example, when determining the diameter of a cylinder, the rod must intersect or cross with its longitudinal axis at a right angle, and when measuring the length, it must be positioned parallel. In calipers of the ShTs-2 and ShTs-3 types there is an additional frame, which is movably connected to the main micrometric adjusting screw (Fig. 3). This design simplifies tool positioning. When taking measurements, the additional frame is fixed on the rod, and the position of the main frame is adjusted by rotating the micrometer screw.

Reading results

Vernier scale

The number of whole millimeters is counted from the zero division on the staff to the zero division of the vernier. If they do not match, then the size contains fractions of a millimeter corresponding to the accuracy of the tool. To determine them, you need to count on the vernier from zero to the line that coincides with the mark on the bar, and then multiply their number by the division value.

Figure 4 shows the dimensions: a – 0.4 mm, b – 6.9 mm, c – 34.3 mm. Vernier division value 0.1 mm

By hourly indicator

The number of whole millimeters is counted on the bar from zero to the last mark not hidden under the frame. Shares are determined by an indicator: the number of the division on which the arrow stops is multiplied by its price.

Figure 5 shows the size 30.25 mm. The indicator division value is 0.01 mm.

By digital display

To determine the internal size taken with a tool with radius measuring surfaces (lower jaws in Fig. 3), their thickness, which is indicated on the fixed jaw, is added to the readings on the scale. To calculate the outer size taken with a caliper with cutters (Fig. 2), their thickness is subtracted from the readings on the scale.

Marking

A regular caliper with pointed measuring surfaces copes with basic marking operations. By pressing one jaw against the side of the part, you can use the tip of the second to draw a line on the surface perpendicular to it. The line turns out to be equidistant from the end and copies its shape. To draw a hole, you need to mark its center: the recess serves to fix one of the jaws. Any technique of descriptive geometry can be used in a similar way.

Carbide tips and cutters leave noticeable scratches on parts made of steels with a hardness above 60 HRC. There are also narrow-profile calipers designed exclusively for marking.

Why do measurement errors occur?

The most common errors that reduce the accuracy of measurement results with a working instrument:

• Excessive pressure on the frame causes misalignment relative to the rod. The same effect is obtained if, when measuring with the lower jaws, the caliper is held by the upper jaws.
• Installation of jaws on fillets, chamfers and roundings.
• Distortions during positioning.
• Instrument calibration violation.

The first three mistakes most often arise from lack of experience, and go away with practice. The latter must be prevented at the stage of preparation for measurements. The easiest way is to set “0” on an electronic caliper: there is a button for this (in Fig. 6 the “ZERO” button). The hour indicator is reset by rotating the screw located at its bottom. To calibrate the vernier, loosen the screws securing it to the frame, move it to the desired position and fix it again.

Deformation of the caliper elements and wear of the measuring surfaces make the tool unsuitable for use. To reduce the number of defects in production, calipers undergo periodic verification by metrological services. To check the accuracy of a tool and acquire skills at home, you can measure parts whose dimensions are known in advance: for example, drill shanks or bearing rings.

Calipers

Probably, many of us had to measure some small details or objects. Often, measuring with a regular tape measure is simply not possible, due to the fact that the object has a round or completely non-standard shape. In this case, you simply cannot do without a tool such as a caliper. This is a special bench tool for measuring the length, internal diameter, or depth of the part you need. It is very convenient to measure round objects (for example, the diameter of a pipe).

What types of calipers are there? There are both small (125-150mm) and big sizes(250-800 mm). It all depends on the size of the part or object you are measuring. For everyday use, a small caliper will be sufficient. The most popular sizes are 125-150 mm, rarely 250. Above these sizes, as a rule, they are used in production.

The accuracy class of a caliper is the error. Those. how accurately you can measure the item you need. The first class has an error of 0.05mm (one twentieth). Second class accuracy error 0.1 mm (one tenth). It is very convenient to measure drills for metal if the accuracy of the hole is very important to you. The difference is that the first class will allow you to measure a cramp with a diameter of, for example, 8.75 mm, and the second class only 8.7 mm. or 8.8mm. This is practically not useful in everyday life. Therefore, the second class of accuracy is “behind the eye”.

How to use a caliper? For example, you have a drill of unknown size. Take it in one hand, the caliper in the other, then you should spread the jaws, then press the drill tightly with them. Next, we look at what division the first (leftmost) mark of the lower scale is located on. Let's say it is located between the numbers 0 and 1, which means the drill is less than 1 cm in size. Next, we look at which division of the upper scale it coincides with. For example, coincides with the 6th division,

We use a caliper

means a drill with a diameter of 6 mm, etc. But the drill does not always have the same amount of mm in diameter. How to find out how many tenths of a millimeter it is larger, since a caliper allows you to measure tenths of a millimeter. Let's say the bottom mark extends beyond the 6 mm border, but does not reach the 7 mm mark. The lower scale has 10 marks, let's see which of the marks on the lower scale will perfectly match one of the marks on the top (only one will match, no more). For example, the 5th mark coincided,

Using a Vernier Caliper

this means 0.5 mm (half a millimeter) needs to be added to the result. Those. This results in a drill diameter of 6.5 mm. Tags are counted starting from the second, the first is not taken into account because if the first mark coincided, then the diameter would be exactly 6 mm, without shares. A caliper of 1st accuracy class has 20 marks on the lower scale, so the measurement is more accurate, but I repeat, it is unlikely that such accuracy will be needed in everyday life.

Next, we'll look at how to measure the internal diameter. There are two pointed jaws on top, insert them between the inner walls of the pipe, for example, then look at the values ​​of the bottom mark, just like when measuring the size of a drill (example above).

It is also possible to measure the depth of an object. To do this, we will use a depth gauge; it is located on the back side of the caliper. For example, let's measure a hole in a wall. We place the end firmly against the wall, then we begin to move the jaws apart, after the depth gauge of the caliper rests, we look at the value on the measuring scale. It is worth noting that not every device has a depth gauge. Pay attention before you buy.

Electronic calipers are, of course, more convenient to use; measurements can be taken faster; you don’t need to look at the scale marks.

Electronic caliper

Especially for beginners and people with poor vision, it will be much more convenient. Although after several measurements, making an accurate measurement will not be difficult. The disadvantages of electronic ones include the price (it is several times higher) and storage conditions. If idle time can be stored at almost any temperature in the garage, then electronics require more careful handling and periodic battery replacement. For comparison, a regular ShTs 125 costs 200 rubles, an electronic one from 700-1500, depending on the model.

It is worth noting calipers with elongated jaws to take measurements of non-standard parts; these are rarely used at home.

It's up to you to decide which caliper to buy, as long as it meets all your needs. Fortunately, nowadays, finding what you need won’t take much time; you can purchase it in online stores with delivery throughout Russia. Good luck with your choice everyone.

For clarity, I made a short video, in case something is written incomprehensibly.

Vernier calipers belong to the group of universal tools that are widely used in the field of mechanical engineering, as well as in enterprises involved in repairs, not to mention private sphere. It is used to obtain internal and external linear dimensions of products. It is also used to obtain the depth of holes. Depending on the model, the maximum measuring range is approximately 0 to 4000 mm. Vernier calipers can be used for marking parts and other technical work.

For measurement, a direct method is used here, thanks to which the actual size of the part being measured is obtained. A standard caliper has three different controllers to obtain dimensions. This may include:

• Jaws for determining external dimensions, which are located at the bottom and allow you to fix the part together when moving;
• Sponges for determining internal dimensions, which are located on top and are spread to the limits of the walls of the hole until they completely rest against both ends;
• A depth gauge, which is located at the rear end and serves to immerse the part being measured (such models were first called Columbus calipers, after the name of the company that first began producing them).

Despite different kinds control elements, the same scale is used for all measurements, since they all move evenly. The caliper has a measurement accuracy of up to tenths or hundredths of a millimeter, depending on the model. To determine these proportions, a vernier scale is used. The calipers are manufactured in accordance with GOST 166-89.

Benefits of Vernier Calipers

A mechanical caliper is a compact and easy-to-use tool. The presence of three types of end control measures helps it find applications in large quantities regions. The device has a fairly high accuracy class, which is useful both in the private and industrial spheres. The caliper scale is made directly on the metal body, so it does not wear off even after prolonged use. The device has only mechanical parts, so its service life is not limited by anything and with careful handling it can all last quite a long time. Thanks to the wide variety of models, you can always choose the most suitable one, especially since the standard ones can be used in many ordinary measuring operations. The caliper has a locking mechanism that allows you to stop the reading in the desired position.

Disadvantages of Vernier Calipers

Vernier calipers have a limited measurement range, which is sometimes not enough for large parts. Any mechanical damage and deformation lead to large errors and render the instrument unusable. During storage, it must be protected from moisture, dust, shavings and sawdust. The measurement accuracy is sensitive to temperature effects, due to the properties of the metal from which the caliper is made.

Classification of calipers

There are different types of calipers, which differ in various parameters. According to modern standards, there are three types of these products, but there are eight types of calipers. The type is determined by what scale the indicator of the device has. Thus, we distinguish:

• (ШЦ) Vernier – the vernier scale of a caliper in which is the main indicator for determining dimensions;
• (ШЦК) Dial - in it the value is shown on a special dial;
• (SCC) Digital - here the data is read by a special electronic device, which issues the final calculation on the digital display of the device.

photo: vernier caliper ShTs

photo: dial caliper ShTsK

photo: digital caliper ShTsTs

It is also worth noting the following varieties:

• ШЦ-1 – universal;
• ShTsT-1 – universal, the jaws of which are located in one direction and are made of carbide materials;
• ШЦ-2 - has a micrometric feed frame.

Eight different standard sizes define the limits of the possible measurements of the device and are often independent of the type.

Technical characteristics of calipers

Device model	Measurement limits, mm	The extension of the jaws when measuring dimensions should be at least, mm:		Reading according to the vernier scale, mm	The permissible error according to the vernier value, mm			Weight, kg
		External dimensions (lower jaws)	Internal dimensions (upper jaws)		0,05	1	2
ШЦI 125	0…125	40	17					0,125
ШЦI 150	0…150							0,150
ШЦII 250	0…250	60	40					0,415
ШЦIII 400	0…400	80	-					1
ШЦIII 500	0…500						-	1,1
ШЦIII 630	250…630							1,3
ШЦIII 800	250…800							1,5
ШЦIII 1000	320…1000							1,7
ШЦIII 1600	500…1600	100		0,1	-			6,4
ШЦIII 2000	800…2000							7,6
ШЦIII 3000	1600…3000	150						29,2
ШЦIII 4000	2000…4000							37,33

Types of calipers

Shts. This includes the ShTs 125 0 1 caliper, the ShTs 150 0 1 caliper and other caliper models. The reading in this form is determined by an additional scale, which is a vernier scale, which helps determine the most accurate number of division fractions. These devices are produced in both the first and second accuracy classes. In the first class, the value of one division of the additional scale will be 0.05 mm, and in the second - 0.1 mm. These products are used to measure linear dimensions and to create markings. The first and second models in this series have a double-sided arrangement of measuring jaws and are among the most popular due to their simplicity and versatility. But the first one is not used to create markup. The second and third are suitable for this, and in the third, only one-sided arrangement of the jaws is made. These models are direct competitors for the bore gauge, but, despite the simplicity and lightness of the design, they cannot be used in hard-to-reach places.

Shtsk. Devices of this type are available in all four possible versions, not counting the various measurement limits in each of them. These devices are relevant for use when reading using a vernier is difficult, or it is required to obtain more accurate results. The main data indicator here is an indicator type device. It ensures that the arrow aligns with the zero division, which is marked on the dial scale.

SCC. These devices are ideal for environments where you want to automate the measurement process, as they provide maximum fast receipt data and instantly display the value on a digital display, without the need to calculate additional scales. One of distinctive features is the presence additional functions, which are not available in all models, for example, such as:

• Memorizing the results that were obtained during the last measurement;
• Displaying the received data on a digital display in metric and inch modes;
• Setting the zero to the required position;
• Backlight;
• Connecting the device to external devices for recording the received data, saving and logging the results.

It is also worth highlighting special modern varieties that stand out from the general standard mass:

• A caliper that has a control system responsible for measuring forces. This device has an electronic control unit that monitors the applied force that is made during the measurement. The reading limit reaches 15 N, and the division value is 5 microns.
• A caliper that has a wireless data transmission system. This is achieved thanks to the built-in Bluetooth module, which can find connected devices at a distance of up to 70 meters. These can be both personal computers and modern gadgets running on operating system Android.
• The computer caliper has a touch screen, as well as a multifunctional display and control system. This device can compensate for errors, including temperature errors, which is quite important when working in various temperature conditions. Also here, measurement results are automatically processed, data can be easily exported to other devices, you can perform software calibration of the device, and also program the automatic measurement process. Here you can find additional modes such as “geometry”, “formula” and others.

photo: computer caliper

Designation and its interpretation of calipers

The design and purpose of a caliper can be determined by its markings, since each of them hides a set of data required to quickly determine the features of the devices. For example, the first letters of the marking are always “ШЦ”, which means the name of the measuring instrument- caliper. Next comes some additional letter, or is simply missing, as in simple models. This can be “C” in indicator models, as well as “C” in digital ones. Next, as a rule, are numbers. The first of them, which is represented by a single digit number, determines the model number “1”, “2”, “3” and so on. The second set is represented by a multi-digit number and indicates the maximum measurement limit that the device is capable of “0-125”, “0-150”, “0-1000” and others.

Using the example of ШЦ1 0-150, we can determine that this is a vernier caliper of the first model, the measurement limit of which is from 0 to 150 mm.

Manufacturers

• Microtech (Ukraine);
• Came To (South Korea);
• Digital (South Korea);
• Miol (China);
• Wenzhou Sanhe Measuring Instrument (China);
• Vemer (China);
• UKC (China);
• Intertool (China).

If you need ropes and climbing ropes at an affordable price, order from us.

Calipers:Video

One of the most structurally simple and widespread measuring instruments, which is distinguished by its versatility, high accuracy of readings and the ability to measure internal and external diameters, is a caliper.

Among its many types, which also have different sizes, you can find options with a truly minimal error.

The tool itself is actively used in everyday life, and in mechanical engineering and turning it is completely impossible to do without it.

Read more about what a caliper is, what it is capable of, what it is made of, what it comes in and which one to choose, below.

Purpose and principle of operation

The purpose of a caliper is to take high-precision measurements inside and outside the objects being measured, as well as the depths of various holes.

The peculiarity of the tool is its versatility.

Shtangel - a common name for calipers among those who constantly use them, is a common abbreviation of the word.

This tool can measure the outer and inner diameters of round and cylindrical objects, such as nuts and bolts, and is suitable for internal groove measurements in all respects.

The principle of measuring with a caliper is to determine the size based on the position of the measuring frame, which moves freely along the rod with a printed scale.

The size value itself is determined by the coincidence method, and its accuracy, depending on the accuracy class itself, can reach hundredths of a millimeter.

Device, characteristics and properties

If you use your imagination, then externally the bar looks like a symbiosis of a hammer and a ruler.

The classic instrument consists of the following elements:

The considered design, which has one-sided jaws, allows one to determine only the external dimensions of objects.

For internal measurements, you will need a caliper with double-sided jaws.

The second ones, as a rule, are smaller in size, located similarly to the first ones, but on the opposite side of the bar, and the working edges are the outer edges.

Material

Metal calipers are made mainly from carbon and of stainless steel, low-alloy tool steels 9ХС, ХВГ.

Stainless steel tools are a classic, however, in the production of modern booms, composites are also used, for example, based on carbon fiber and polymer resins.

Dimensions

Typical sizes of classic calipers:

• Jaw length for external measurements: 35 – 300 mm.
• Jaw length for internal measurements: 6 – 22 mm.
• Measuring range – up to 2 m.
• Vernier length: 9 – 39 mm.
• Weight (depending on material and dimensions): 0.2 – 8.9 kg.

Models with a measuring range of up to 5000 mm can weigh more than 35 kg.

GOST

The following current GOSTs regulate both the verification and production of calipers:

• GOST 166-89 – defines technical conditions
• GOST 8.113-85 - determines the verification procedure

Accuracy

Vernier calipers are characterized by several accuracy classes:

1. class - error is 0.05 mm (twentieth of a millimeter)
2. class - error is 0.1 mm (tenth of a millimeter)

For high-precision measurements, a completely different instrument is used - a micrometer.

To clearly show what the accuracy class affects, it is enough to assume that it is necessary to determine the diameter of several drills without markings.

A second-class accuracy bar will allow you to find drills with a diameter of 6.7 or 6.8 mm, and a first-class one with a diameter of 6.75 mm.

For electronic instruments, the error may reach 0.01 mm.

Verification

While working with a caliper, there may be a violation of its settings, various deformations of individual elements, and simple wear.

All this affects the accuracy of the measurements, which, moreover, can be distorted by adhering dirt, grease, or metal filings covering the instrument with a magnetized layer.

Important!

Every owner of a boom needs to handle it with care and keep the tool clean.

In order to avoid various distortions in measurement results, the instrument is checked annually.

To do this, just contact a specialized service center for setup and repair.

Based on the verification results, a corresponding certificate is issued.

At home, you can perform a simple check of the correctness of the readings by pressing the jaws of the caliper all the way.

In this case, the zero strokes must match.

Marking

• ШЦ-I – allows you to determine external and internal dimensions using two pairs of jaws. The depth of the holes is determined using an appropriate ruler.
• ШЦ-IC – readings are simplified due to the dial head, the gears of which are engaged with a rack installed in the rods.
• ShTsT-I – one-sided jaws have a hard-alloy coating. Used in conditions of increased abrasiveness.
• ШЦК - used where high measurement accuracy is not required, since readings are taken from a circular scale, which is based on a spring mechanism.
• ШЦ-II – a frame feeding mechanism has been added to the double-sided jaws, which allows marking.
• ШЦ-III. Characteristic– single-sided jaws and large sizes. Unable to measure depth.
• ШЦЦ – readings are taken on a digital scale.

Types of calipers and their prices

Calipers are divided into the following main types:

Analog

The counting is carried out according to the vernier. Another name is vernier. Cost – from 400 rubles.

Switch

Does not require calculations, easier to use, since the measurement results are displayed on the dial with a dial scale.

Cost – from 1700 rubles.

Digital

With a small display on which the measurement results are displayed digitally. Has the highest accuracy.

Another name is electronic. Cost – from 700 rubles for the simplest models.

In addition, booms come with a depth gauge ( type T-I and I) and without it (types II and III).

Precision calipers is a general name for models with increased measurement accuracy.

By the way, a monoblock instrument (fixed jaws are not fixed to the rod, but are an integral part of it) gives the most accurate readings.

There are tasks that a standard tool simply cannot handle.

Then the master picks up a special caliper.

Special calipers

Vivid examples of specialized models:

Marking

With sharpened carbide jaws and a special compass mechanism.

In addition to taking measurements, it allows you to draw arcs directly with sponges on solid material.

Marking calipers are similar to options without a compass mechanism with jaws based on hard alloys.

Price – from 2.5 thousand rubles.

For brake discs (ШЦЦД)

Design with one-sided extended jaws for external measurements, having work surface teeth to improve measurement accuracy.

There are options that allow you to determine the thickness of brake discs on cars and motorcycles without the need to dismantle the wheel.

The cost of the simplest models is about 1 thousand rubles.

Traveler

To measure the parameters of the rail surface.

Price – from 20 thousand rubles.

Analogs of calipers include the following measuring instruments:

A tool designed to measure rack and pinion teeth with an accuracy of 0.02 mm.

A tool designed to measure depths and heights of blind holes, protrusions, grooves, and grooves.

A tool that allows you to measure heights without specialized skills and make vertical markings of parts with an accuracy of 0.05 mm.

Another name is height gauge.

How to choose a good caliper?

The main advantages of the barbell are its measurement accuracy.

For this reason good tool, first of all, it must be made of durable material, have easily visible markings and withstand active use.

Popular with experienced craftsmen A stainless steel caliper with engraved divisions is used because of its high corrosion resistance and durability.

Main principles of selection:

• Length – determines the measurement range. Selected depending on the task. For everyday use, a 125 mm tool will be sufficient, but for building a house, for example, you will need a 5-meter boom.
• Measurement step. Roughly speaking, the measurement result is more accurate for models with the smallest distance between adjacent scale divisions.
• Cost – there is no need to buy an expensive model for infrequent household use However, a good boom cannot be cheap. For craftsmen whose main measuring instrument is a caliper, it is better to look towards proven Japanese, German and Swiss models. A high-quality caliper, especially an electronic one, is a fairly expensive tool that is bought once, one might say, for life. This is what we should build on.

Before purchasing a caliper, you should make sure that there are no backlashes between its moving and stationary parts, as well as that the zero marks of the two scales coincide when the jaws are closed.

What you need to know about calipers?

The caliper needs careful, careful handling, as the following factors can reduce its accuracy and distort the measurement results:

• Damage to work surfaces. Even the presence of small nicks or scratches can be decisive.
• Lack of strict parallelism between the jaws, or their wear.
• Accumulated dust or dirt between the moving parts of the caliper.
• Zero readings are not set correctly.

The instrument is stored in a case, which must be included in the kit.

Manufacturers of calipers

The following manufacturers manufacture calipers:

• TOPEX
• MEGEON,
• KRIN,
• MATRIX,
• CNIC
• GRIFF,
• CALIBRON,
• MITUTOYO.