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30+ Measuring Instruments for Mechanical Engineer

Here are 30 Measuring instruments for mechanical engineer. Every Mechanical Engineering student or employee should know about this.

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01. Vernier Caliper

Vernier Caliper is a widely used linear measurement instrument with a least count of 0.02 mm. It is used to measure linear dimensions like length, diameter, depth.

vernier scale name

It is Basic Instrument of measurement, consist of two types of scale

The main scale and the Vernier scale that can slide along the main scale. Two types of measurement we can do, the first one is through the external jaw (measure external dimensions) and another one is internal jaw (measure internal dimensions).

02. Outside Micrometer

External Micrometer is also known as Outside Micrometer or External Micrometer.

It is used to check outside diameter of circle by the means of accuracy of 0.01 mm or up to 0.001 mm.


Vernier type Micrometer gives highest acceptable accuracy of 1 micron such gauge is vernier type micrometer.

03. Vernier Height Gauge

Vernier height gauge used to measure vertical dimension from reference ground. Vernier Height Gauge consist of a graduated scale or bar is held in a vertical position by a finely ground fixed base.

The graduated scale has least count of 0.02 mm like Vernier Caliper has. And the way of taking a reading of measurement in Vernier Height Gauge is same as in Vernier gauge.

mitutoyo Vernier Height Gauge

04. Steel Scale

Steel scale is single piece linear measuring instrument.

Steel scale indicates two units that are cm and inches, cm division on one side and inches, on another side.

steel scale

05. Vernier Depth Gauge

Vernier Depth Gauge as the name suggests is used to measure the depth from the surface of reference of an object.

Vernier caliper also has depth bar but this can not be used as the standard measurement.

06. Vernier Bevel Protractor

A simple protractor is a basic device used for measuring angles with a least count of 1° or ½°. Bevel Protractor is an angular measuring instrument capable of measuring angles with a least count of  5’.

vernier bevel scale

The protractor dial is graduated in degrees with every tenth degree numbered. The sliding blade is fitted into this dial I.e. it may be extended to either direction and set at an angle to the base.

mechanical course

07. Plunger Dial Gauge

plunger dial gauge

The dial indicator or the Plunger dial gauge is one of the simplest and the most widely used mechanical comparator.

First of all the use of plunger dial gauge used to compare work-pieces against a master

08. Lever Dial Gauge

parts of lever dial gauge

Lever Dial Gauge also knew as Test Indicator. It used to measure sensitive contact.

Lever Dial gauge usually measure up to 0.80 mm. But some special type lever dial design for measurement up to 2 mm. 

lever dial gauge

09. Engineering Square

A ruler can be used to draw straight lines but there is no quarranty that the line drawn is accurate and exactly straight,this is where the engineering square is brought into use.

engineering square

An engineering square also known as machinist square is similar in size and construction to a try square.

It is a tool used for making straight lines and are used to measure angles.

10. V Block

In Industries where precise marking and firm holding of objects is required, V-Blocks play a major role and are extremely important metalworking jigs.

The construction had two clamps:screw clamp and a U shaped handle like clamp and a V-block .


11. Radius Gauge

Gauges are derived from the French word”jauge” which means the result of the measurement. We are all aware that gauges are used to measure the thickness, size or capacity of something.

concave and convex shape

Likewise, radius gauges are instruments that are used to measure the radius of the object.

blades of radius gauge

The radius gauge is combined with another gauge known as fillet gauge which in mechanics means a rounding of the part design.

12. Digital Vernier Caliper

Digital Vernier Caliper is upgrading version of Analog Vernier Caliper, which is a widely used linear measurement instrument with a least count of 0.01 mm, more accurate than Analog.

This Digital type of vernier is similar to Analog Vernier Caliper Instead Dimension output in Digital Manner that is more convinces than analog type.

digital vernier mitutoyo

It also consists of two types of scale –

The main scale and the Digital display that can slide along the main scale. Two types of measurement we can do, the first one is through external jaw (that measure external dimensions like shaft) and another one is internal jaw (measure internal dimensions like hole).

13. Digital Micrometer

Digital Micrometer is a very popular instrument these days because of its easy of compactness of taking an observation.

Digital Micrometer can observe measurement in mm or inch depend upon our need basis.

digital micrometer

14. Inside Micrometer

Inside Micrometer is used to measure the larger internal dimension. Inside Micrometer can measure the internal Diameter of holes and registers.

inside micrometer mitutoyo
Mitutoyo’s Inside Micrometer

Types of Micrometer

There are various types of micrometers available in the industry each used for a specific purpose. One such micrometer is the “Inside Micrometer”.

The inside micrometer is used to measure the inner diameter of objects that are bonded by walls,cylindrical bore or hollow pipe.There are two types of Inside Micrometer

  1. Analog type Inside Micrometer
  2. Digital type Inside Micrometer

15. Depth Micrometer

We also measure depth through Vernier caliper, but Vernier caliper does not deliver as much as accuracy and precision, because extension rod of Vernier caliper has no standard, it used only for comparison purpose.

Depth micrometer used to measure the depth of an object with precision and accuracy with least count of 0.01 mm. The measuring span is 25 mm just like in micrometer, that can change by changing upsetting rod.

Depth Micrometer by mitutoyo

16. Measuring Tape

Measuring tape is used to measuring long distance.


17. Digital Height Gauge

The electronic Height gauge is very compact, simple, easy to use instrument widely used in industries, tool rooms, workshops etc.

Some think you should consider while handling Electronic Height Gauge, Because of the cost of Electronic Height gauge matter in any industries or organization.

18. Electronic Height Gauge

Electronic height gauge is advance form of height gauge. It has higher accuracy and multi function.

An Electronic height gauge can measure diameter,angle, parallelism, squareness along with length.

trimos height gauge

19. Digital Universal Caliper

Digital universal caliper is widely used for measure inner and outer length of work-piece

universal caliper

20. Sine Bar

sine bar

Sine bar is a precision angle measuring instrument along with slip gauges. The name suggests that Sine bar work on sine principle. Slip gauge used to build up the height of sine bar.

The required angle is obtained when the difference in height between the two rollers is equal to the Sine of the angle multiplied by the distance between the centers of the rollers.

21. Digital Protractor

Digital Protractor measure an angle over 360 degree with a high accuracy of 0.1 degree. Digital Protractor is very simple and ease to measure angle by just putting between levels or surface.

Digital protractor mitutoyo

22. Spirit level

To check level of any surface or table, spirit level is used for leveling.

spirit level

23. Slip Gauge Set

slip gauge set

Slip Gauge is set standard size rectangular shape block. Slip gauges are available in standard sets in both metric and inch units.

In metric units, sets of 31, 48, 56, and 103 pieces are available.

For example, the set of 103 pieces consists of the following:

  1. One piece of 1.005 mm
  2. 49 pieces ranging from 1.01 to 1.49 mm in steps of 0.01 mm
  3. 49 pieces ranging from 0.5 to 24.5 mm in steps of 0.5 mm
  4. Four pieces ranging from 25 to 100 mm in steps of 25 mm

24. Bore Dial Gauge

bore dial gauge

Bore Dial Gauge use to measure the inner diameter of the hole, it is gauge fitted with a plunger dial gauge. In this video, you are able to know how to measure diameter with a bore dial gauge.

Bore dial gauge used within the standard range that means bore dial gauge have a standard set of pins(anvils) with the variable range of up to 2 mm.

25. Feeler Gauge

A Feeler gauge is used to measure the clearance between two parallel flat faces for example piston and cylinder. As the name suggests, feeler gauge called as to measure neither tide nor freely.

feeler gauge

Feeler gauges are used for measurement of clearances.

It is a tool that measures air or narrow gap widths between two surfaces in engines and machinery.

Feeler gauge available in no. of the blade like 10,13,20 and 28. With a step of 0.05 and 0.10 mm.

26. Thermocouple

Thermocouple consist of two dissimilar conductor wire, made from different metals. These wire are welded together at one end, form a junction used to measure temperature.


27. Thermister

Thermistors have a high coefficient of resistivity. Thermistors are made of semiconductor of solid type.

The suitable temperature measuring range for thermistor is -100 degree Celsius to 300 degree Celsius. Some special type thermistor can measure up to 600 degree of temperature.


The change in temperature is measured by changes in its resistance. So, the Wheatstone bridge circuit is used for it.

Also, thermistor can convert changes in temperature to corresponding changes in voltage as a current.

28. Barometer

Air gets pulled down by gravity and hence air exerts pressure on objects. One such example of measurement is known as a barometer.

Barometers are scientific instruments that are used for the measurement of atmospheric or air pressure. It is an important and essential tool used in the meteorological department for forecasting short term weather and altitude changes.

The barometers should be kept at the same level and cannot measure air pressure above the altitude of 5,000 feet. Initially, water-based barometers were used, later it was replaced by mercury and aneroid barometers which the two most commonly used barometers.

29. Snap gauge

Snap gauge is GO and NOGO type gauge. That means snap gauge consist 2 fixed measured distance or gap, one is known as GO and another one is known as NOGO.

snap gauge how

30. Plain Plug gauge

Plug gauge is used for assessment of hole or diameter of an object. With specified tolerance of GO and NOGO side, plug gauge is also known as pin gauge.

Behalf of checking the diameter plug gauge also use in comparing, setting, calibrating of other gauges.

plug gauge


In an electric circuit, even if the switch or loop is closed, it is difficult to know whether the current is flowing, hence for this purpose galvanometer was introduced in the circuit.


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6 thoughts on “30+ Measuring Instruments for Mechanical Engineer

  1. Great, thanks for

    1. Thanks for writing in Deepanshu

  2. Thank you so much ☺️

    1. Thanks chethan

  3. measurements standard may differ for various conditions. are you agree

    1. Hi,
      Thanks for writing!
      Yes, of course. its depends upon environmental conditions, coefficient of thermal expansion of material, master used, operator skills etc.

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