Q: What are the Parts of a Dial Caliper and Their Functions?

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In today’s world, dial calipers are used far more frequently than Vernier calipers. Day by day it becomes a favorite tool to mass people because of its dial indication. The dial indication is located in the middle of the device, making dial calipers significantly simpler to use and read.

The dial on a dial caliper is moved in increments of one-thousandth of an inch by a mechanical system that consists of a rack and pinion. Taking precise measurements with a caliper requires familiarity with its components and their functions.

In this article, our caliper experts briefly explain about what are the Parts of a Dial Caliper and Their Functions.

What are the Parts of a Dial Caliper and Their Functions
What are the Parts of a Dial Caliper and Their Functions

10 Major Parts of a Dial Caliper in 2024

A dial caliper consists of ten primary components. They all are important to know when we are measuring with a dial caliper. We’re starting with the Jaws,

1. Upper Jaws

There are mostly two upper jaws present. The upper portion of the scale is where you’ll find these jaws fastened. One of the jaws is set in place, while the other jaw can move freely.

When taking inside measurements with a caliper, such as the diameter of a hole or slot, the upper jaws of the instrument are employed. Before obtaining a reading, the jaws are opened till they touch the margins of the things being examined.

2. Lower Jaws

Similarly to the upper jaw, one of the lower jaws is permanently fastened to the main scale. These jaws are fixed jaw and attached to the scale, while the other can be moved.

These teeth (jaws) are optimized for a secure grasp on objects. We can take outer measurements so spontaneously. With the help of this part of the caliper, we can measure diameter, width, and length.

3. Dial caliper depth rod

Towards the end of the main scale, there is a narrow rod it’s called the caliper depth rod. It’s easy to gauge depth using a rod. The primary scale’s edge rests on the top of the thing being measured. The next step is a gradual opening of the mouth. The depth rod is lengthened when the jaws are opened.

When the depth rod reaches the bottom of the object, the jaws can close. Using the depth rod, we can determine how deep each jar is. This component’s borders are all that are visible when the jaw is closed because the slider is brought closer to the fixed jaw.

Two major things are our major functions of depth rod. One is when the mouth is wide open, our experts notice that the depth rod becomes more apparent. The other is with more breadth, the depth rod looks to be longer.

4. Dial

Dial plays an important role when we’re measuring is on the process. The dial shows us the value being measured alongside the main beam scale. The Dial can display measurements within a ten-thousandth of an inch.

If you want to measure to the ten-thousandths of an inch, you’ll need to measure between the marks on the dial, which represent one-thousandths of an inch.

5. Indicator Needle

Now comes the indicator needle. You will notice that part when you expand the caliper’s jaws or stretch the depth rod, the indicator needle spins around the dial.

The beam scale reference edge will advance by one increment for every full turn of the dial (2mm or approx. 0.1 inches).

6. Dial caliper lock screw

The lock screw helps the user to keep the jaws in position when an object is securely wedged between the jaws. With this little help user of the caliper can take measurements without any hassle of holding the jaws. The time when we lock the screw tight, the jaws will remain firmly closed.

This action we have taken allows the object to be measured to be removed from the device without losing its position. After adjusting the slider to accommodate a specific object size, the lock screw stops the slider from further movement.

It works to prevent movement at any cost. Once the slider has been adjusted to the correct position, corresponding to the size of the object, it will remain in that position permanently. This will allow for a precise analysis.

7. Dial caliper reference edge

The reference edge comes into action when keeping track of the greater increments of measurement. It helps to determine the length of an object to an accuracy of a ten-thousandth of an inch.

It also utilizes the dial and pointer on the ruler. The blade is the instrument that is used whenever there is a need to determine the depth of an object.

8. Dial caliper main scale

The dial caliper features a sizable scale that extends throughout its entire length. Its primary scale can display either centimeters or millimeters, depending on the situation. In the SI system, 1 mm is the smallest increment of the main scale. The main scale remains unmoving.

9. Dial caliper thumb screw

Turing the thumb screw is very much handy. The precise adjustment of the caliper’s measurement faces is accomplished by turning the thumb screw (both sets of jaws and the depth rod).

Because of this aspect, the individual who is doing the measuring will have a higher sense of control over the substance they are analyzing.

10. Dial caliper bezel nut

The bezel might not play a significant role in the placement of the object, but having it will help you get the right result. After the caliper has been calibrated, the exact settings that were chosen for the dial are secured by the bezel nut.

This helps to verify that the dial is positioned in such a way that it reads zero before commencing the process of taking measurements.

Related: Digital vs Dial vs Vernier Calipers: Which is More Accurate?


Dial calipers have replaced vernier calipers as the standard measuring tool. Dial calipers’ primary innovation—the dial indicator—greatly simplifies their use and interpretation. Learning how to use a dial caliper is crucial if you want precise measurements. It’s best to inquire about Dial calipers and other types of calipers if you want to understand more about them.

Make sure to ask questions if you don’t understand anything. Our experts are always at your service 24/7.

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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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