How to Read a Dial Caliper in Inches, mm & Fractions in 2024

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Dial calipers are becoming increasingly popular in the industrial business. Why? Because it’s so spot-on in accuracy. The outside diameter, length, height, and thickness of an item can all be measured with dial calipers.

Dial calipers’ inner contacts can be used to gauge a component’s inner diameter. A rack and pinion device translates the movement of the caliper jaws to the dial indicator. Dial calipers are made easier to use and read by the dial indicator, which is positioned in the center of the device.

Dial caliper readings are a mystery to most newcomers. We’ll walk you through the process step by step in this article.

How to Read a Dial Caliper in Inches and mm
How to Read a Dial Caliper in Inches and mm

How to Read a Dial Caliper in 2024

The dial caliper must be handled carefully and properly. When measuring using a dial caliper, it is necessary to comprehend the entire process. The reading of the caliper is simplified by dividing the work into many steps.

There are ten steps listed below to comprehend the read of the caliper.

Step 1

In the first step, you have to know the main parts of the dial caliper. There are six parts in the dial caliper. You have to understand their work and know when to use which one. Work on the six parts of the dial caliper

  • First, there are an object’s inner faces, which are utilized in the process of measuring an object’s interior length. The outer faces are used to measure anything that may be placed between them.
  • The next component in the sequence is the reference edge, which is used to maintain track of larger measurement increments.
  • Next in the series are the dial and pointer. They were both capable of measuring the length of an object with an accuracy of one ten-thousandth of an inch.

The knife’s sixth and last essential component is the blade. The blade is the instrument utilized for measuring the depth of an object.

Step 2

Then you must completely close the caliper so that no light can be seen through the jaws. If there is, the caliper must be completely cleaned, or there is a metal burr on the jaws that must be removed.

Step 3

In the step, you have to zero the dial caliper. It is very much essential to get an accurate result from the caliper.

Step 4

Make sure the thing you’re going to measure has been cleaned. This can have a considerable impact on the accuracy of the measurement if they are not cleaned with care, as this might cause contamination.

Step 5

The position of the jaw changes in response to the object being measured. Depending on what is being measured, choose whether the inside or outside of the jaw should be utilized to take the measurement.

On the exterior, thickness, length, and width are measured, while on the interior, gaps and holes are measured.

Step 6

In this stage of the process, you will need to open the jaws and take a measurement of the component. When closing the jaws, there should be a feeling of snugness, yet the part should be able to easily slip into and out of the jaws without causing any complications. To keep the position of the caliper from moving, you need to tighten the lock screw.

Step 7

Learn the meanings of the markings before attempting to calculate the measurement: The number that the needle is currently pointing to on the dial indicator needs to be stated in thousandths; thus, you need to multiply by whatever number you obtain after doing the calculation.

Each mark represents one-tenth of an inch, or .1, and every ten marks equal one inch (2.5 centimeters). In addition, every ten marks equals one inch. 001.

Step 8

There are mainly two types of values that come from the measurement; one is reading from the scale, and the other is reading the dial. To the left of the dial indicator on the caliper is a straight edge.

First, determine how many inches the straight edge has traversed, then determine how many tenths it has traversed, and record both quantities. Observe the indicator dial, locate the number now under the needle, multiply it by 001, and record the result.

Step 9

After that, you have to add all of the numbers while ensuring that the decimal places are accurate.

Step 10

You also need to be familiar with the constraints imposed by the dial caliper. The maximum length that can be measured with the dial caliper is six inches, as it can only measure up to that point.

A dial caliper allows you to take four different measurements: the outside diameter (also known as the item thickness), the inside diameter (also known as the space width), the step distance, and the hole depth.

Preparation Before Using a Dial Caliper

Before beginning the measuring procedure, there are a few stages that need to be completed in order to obtain an accurate result.

  • First, You should wipe down the measuring surface of the object being measured with a clean cloth or one that has been soaked in cleaning oil to ensure that it is dry and clean.
  • After that, A dry or cleaning oil-soaked towel is all that is needed to clean the dial caliper after you remove the protection label.
  • Next, turn the dial caliper’s beam lock to its most loosely regulated level.
  • Then, To clean the caliper’s four jaws, use a clean towel or one soaked in cleaning oil, and make sure the measuring surfaces are completely dry.
  • Finally, The dial caliper must be entirely closed before you can determine whether or not the needle is pointing to zero. You can begin taking measurements immediately if it’s pointed to zero.

Related: Digital vs Dial vs Vernier Calipers: Which is Better?

How to Read Dial Caliper in Inches 2024

There are four main parts when you read the caliper into inches. They are main scale reading, dial scale reading, zero error, and making the final calculation. To understand let’s try with an example.

Example: Suppose you are measuring a thing where you see that the main scale reading is 7 and the dial reading is 53 and it matches with zero.

The caliper that we are using has a primary scale that can measure up to 1 inch in increments of 10 and a dial scale that can measure up to one full turn in increments of 200. If the jaw moves 0.2 inches (0.20 centimeters), then the needle will go through one full rotation.

Answer: First we’ve to understand the scale. Then we go for the total measurement calculation. The dial scale we’re using there is two parts main scale and the dial. Here,

The primary scale’s smallest division value is 0.1″ (1″: 10 divisions). The dial scale has 200 divisions for every inch, with the smallest number being 0.001 inches (0.2 inches).

Now we’re going to the measurement and calculation section. First, we are proceeding with the main scale reading.

1. Main Scale Reading

It is imperative that we focus our attention intently on the pointer on the left. The number of divisions that are accomplished by the sliding jaw is 7, and the smallest division value that the main scale can achieve is 0.1 inches.

There is a formula for main scale reading. That is,

Main scale reading= Divisions passed by jaw × Smallest division value of the main scale. So,

we get from the main scale is

=> 7 × 0.1″

=> 0.7″

Now we have to head to the dial scale reading.

2. Dial Scale Reading

Here we have to Look at the right pointer. The amount of divisions passed by the needle is 53 and the smallest division value on the dial scale is 0.001″.

The formula for dial caliper is,

Dial scale reading= Divisions passed by needle × Smallest division value of the dial scale. So,

=> 53 × 0.001″

=> 0.053″

3. Zero Error

We know that when we’re closing the jaw of the caliper both of them are level to zero. There’s no error occurred. So’

=> 0 × 0.001″ = 0″

4. Final Reading

In the final reading, we’ve to calculate the total. Where the formula is,

Final reading= Main scale reading + Dial scale reading − Zero Error

Here we’ve to add both scale readings and subtract the error if there is one found. We found that there’s no error found. So final reading is

=> 0.8″ + 0.051″ − 0″

=> 0.851″

How to Read Dial Caliper in mm (Millimeter) 2024

There aren’t that many differences in the calculation of inch and millimeter readings.

Suppose that the main scale reading is 25 and dial scale reading is 0 and the error is also zero. We have to calculate the final reading.

First things first, let’s get an understanding of the scale. The scale that we are making use of over there,

The smallest division value on the main scale is 1 mm, while the smallest division value on the dial scale is 0.02 mm. One centimeter is equal to 10 divisions (2 mm: 100 divisions)

1. Main Scale Reading

The formula is similar to the previous section of the inch. Here,

The main scale reading= The divisions passed on the main scale × Smallest division value of the main scale. So,

=>25 × 1 mm

=>25 mm 

2. Dial Scale Reading

Then comes the dial scale reading. Here the formula is

Dial scale reading= The divisions passed on the dial scale × Smallest division value of the dial scale. So,

=> 0 × 0.02 mm

=> 0 mm

3. Zero Error

When the jaws are totally closed, the needle will point to the number “0” when it’s in this position. So,

=> 0 × 0.02 mm

=> 0 mm

4. Final Reading

Like the previous formula, we’ve to add and then subtract the zero error. Her formula is,

Final reading= Main scale reading + Dial scale reading − Zero error reading. So,

=> 28 mm + 0 mm − 0 mm

=> 28 mm

Measuring Range of Dial Caliper in 2024

Each and every caliper in existence comes with its own unique measuring range. The difference between the highest value and the smallest value that a caliper is capable of measuring is referred to as the measuring range of the device.

The majority of dial calipers have a measuring range of 150 millimeters (six inches). But some industry workers need a bigger caliper to measure the object. You will easily find additional calipers available with ranges ranging from 100 millimeters (four inches) to 300 millimeters (twelve inches).

Some Most Commonly Asked Questions About (Dial Caliper Reading): FAQs

What is the least count of dial indicators?

There is a maximum number of dial indicators that can be counted. Dial indicators typically have a minimum count of 0.01 mm that can be obtained by using the instrument. It takes readings in the range of 0.25 to 300 millimeters for the measurement.

How do you read a dial indicator in mm?

Use the line that is most visible from above and to the left of the dial gauge head’s leading surface. That is all you are required to do. For instance, if the highest visible line is positioned two unnumbered lines above the numbered line 4, then the measurement must be recorded as 4.2 centimeters. The reading must then be converted to millimeters and multiplied by 10.

What does a dial indicator measure?

Dial indicators are common in precision engine manufacturing. Deck clearances, crankshaft thrust and straightness, lifter travel, and other tests involving the distance between surfaces or component travel are common uses.

Final Verdict on a Dial Caliper Reading in 2024

Dial caliper reading isn’t a difficult task. Using a caliper is a simple process if you follow the steps properly and avoid making mistakes.

I wish you all the best in your future endeavors. Stay with us to learn more about calipers. Thank you, and have a wonderful day.


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Calvin Cameron

Hello, I'm Calvin Cameron. I'm a metalworking specialist for more than a decade. As a metalworker, I've been working in various areas like automotive plants, jewelry shops, and shipyards. I'm experienced with a lot of machines, tools, and materials. This is my loving area where I can talk and share about tools, measurement, and provide accurate data. Hope you will find some really good things from my research and studies. Enjoy reading.

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