Best Depth Micrometer

A depth micrometer, as the name suggests, is used to measure depth. It is a very sensitive tool generally used by machinists and engineers for measuring the depth of holes, bores, shoulders, slots, etc. However, a general rule, to get the best measurement result of depth measurement, you have to pick the best depth micrometer and that’s the reason of this article.

Actually, you can use a vernier depth calipers to measure depth of holes. The advantage of depth micrometer is it offers you better accuracy and precision than a depth caliper.

In a basic depth micrometer, you get a moving spindle, the base part, a ratchet that you rotate to get the depth reading, a barrel/sleeve with a scale (main scale/ barrel scale), and a thimble with an auxiliary scale that rotates when you rotate the ratchet. You also get a thimble lock screw to lock the reading of the micrometer.

Using a depth micrometer is pretty similar to that of a micrometer screw gauge except for the fact that its main scale is reversed and the zero of the main scale is on the right side. To measure the depth of a hole using a depth micrometer, gently insert the provided rod in the base hole and turn the dial to descend the rod inside the sleeve until its end touches the base.

ProductsPicturesAccuracySpecial Feature
Price
1. Starrett 440Z-6L Vernier Depth Gauge

±.0001”Hardened and ground base measuring surfacesCheck Price!
2. Brown & Sharpe 599-603-143-3
±0.003 mm
Satin chrome finish for glare free readingCheck Price!
3. Brown & Sharpe TESA 60.30069
±.0001"
(0.003 mm)
Digital interfaceCheck Price!
4. Accusize Industrial Tools 2025-4201±0.003 mmClear and microfine graduations
Check Price!
5. Fowler 52-225-226-0±0.5%Comes with six interchangeable rods
Check Price!
6. Mitutoyo 329-351-30.0001"
(0.001 mm)
Offers wide measuring range
Check Price!
7. Mitutoyo 129-132±3µm
Adjustable measuring rods
Check Price!
8. Fowler 54-225-456-0
.00016″
(0.004 mm)
Auto switch off LCD display
Check Price!
9. Starrett 449AZ-3R±.0001"
Ideal for narrow recessions
Check Price!
10. Mitutoyo 128-105±0.003 mm
Satin chrome finishCheck Price!

Top 10 Best Depth Micrometers in 2023

1. Starrett 440Z-6L Vernier Depth Micrometer [Best Overall]

Starrett 440Z-6L best depth micrometer overall

So, the first depth micrometer that we have on the list is from the Starrett brand which is known for producing high-quality and high-accuracy products. You get 4 adjustable measurement rods in the list that cover the range of up to 9 inches. The resolution of this micrometer is about 0.001mm which results in providing very precise results.

The base of the micrometer and the measuring surfaces are ground, hardened, and lapped which results in added durability and are the indicators that this depth micrometer is a premium tool.

buy now!

Pros:

  • Ring type nut to easily secure readings
  • High Accuracy
  • High resolution

Cons:

  • You have to manually calculate the measurements from the readings

2. Brown & Sharpe 599-603-143-3 Vernier Depth Gauge Micrometer

Brown & Sharpe 599-603-143-3 depth micrometer

Our next depth micrometer in the list is the Brown & Sharpe 599-603-143-3, which can be a great choice for you if you are looking for a tool that offers you a very high resolution of .0001 inches. The vernier scale of this micrometer comes with a very fine and crisp graduation that makes reading much easier.

Furthermore, the hardened base of this depth micrometer ensures uniform pressure on the surface and the fraction thimble ensures that you get accurate readings. Along with this micrometer you get three 0.125” measuring rods that are made from stainless steel.

buy now!

Pros:

  • Satin chrome finish for no glare
  • 4 inch long base for uniform pressure
  • Comes with a wooden case for extra care

Cons:

  • No lock nut

3. Brown & Sharpe TESA 60.30069 Swiss Made Digital Depth Micrometer

Brown & Sharpe TESA 60.30069 best digital depth micrometer

If you are someone who absolutely hates doing precise calculations with extra consideration then this one’s for you.  It can be a great choice when you want to be quick. The Brown & Sharpe TESA 60.30069 Digital Micromaster Depth Gauge is a digital depth micrometer and comes with an LCD display that gives you the result on the spot without any complicated calculation.

You get a range of 7 inches on this micrometer along with the U.S metrics. As it is a digital micrometer, you also get a 3-volt lithium battery with it. You get a resolution of 0.001mm on this tool.

buy now!

Pros:

  • Very easy to use
  • Battery included
  • Comes with multiple rods

Cons:

  • The display unit is made from plastic

4. Accusize Industrial Tools Tools 2025-4201 Base Depth Micrometer

Accusize Industrial Tools depth micrometer is a premium quality tool that comes with 6 measurement rods that give you the range of about 6 inches. You get a wide range of measurements with the resolution of 0.001 mm. The satin chrome finish prevents the reflection of light on the graduation so you don’t have any hurdle while taking the readings. A fitted wooden case is included in the package.

buy now!

Pros:

  • Quick and easy adjustment
  • Ideal for small holes
  • Accurate results

Cons:

  • No digital display

5. Fowler 52-225-226-0 Digit Counter Depth Micrometer


The Fowler 52-225-226-0, Digit Counter Depth Micrometer comes with a digital counter along with 6 measurement rods, each of them is 0.176”. They offer you a range of 6 inches and resolution of 0.001 mm. The satin chrome finish makes this micrometer wear resistant. You also get a wooden case in the package. The manufacturer offers you a 1 year warranty with tools.

buy now!

Pros:

  • Quick readings
  • Locking clamp
  • 1 year warranty

Cons:

  • The display unit is made from plastic

6. Mitutoyo 329-351-30 Depth Micrometer

Our next choice is from a well-known brand which offers a wide range of quality tools. It is the Mitutoyo 329-351-30 DMC4-12″MX Depth Micrometer with a resolution of 0.001 mm. It is the best choice if you want to cover deeper holes as its 12 rods cover a range up to 12 inches. The display unit is digital and does not require much effort. The battery for the display unit is included in the package.

buy now!

Pros:

  • Quick and easy use
  • Easily interchangeable rods
  • Covers wide range

Cons:

  • No warranty

7. Mitutoyo 129-132 Depth Micrometer

Our next pick is Mitutoyo 129-132 which is also from the same brand and hence is a premium product. But this one is an analog depth micrometer. You get 5 rods that can easily be interchanged and cover 6 inches of range. It is covered with a satin chrome premium finish that makes it more durable. The 4 inch base uniformly distributes the pressure for more accurate readings.

buy now!

Pros:

  • Multiple rods
  • Satin chrome finish
  • High Accuracy

Cons:

  • Case is made from plastic

8. Fowler 54-225-456-0 IP54 Digital Depth Micrometer

The Fowler 54-225-456-0 digital depth micrometer also comes with an electronic counter with a digital display unit that is resistant to water and dust (IP65 rating). The microlapped 4 inch base allows you to take repeated measurements with greater accuracy. You get an inch and metric units on the micrometer with the resolution of 0.001mm and 0.0005 inches. The easy to adjust 6 interchangeable rods come with a diameter of 0.176 inches.

buy now!

Pros:

  • Hardened and ground steel for added durability
  • Quick and easy measurements
  • 2 lithium batteries included

Cons:

  • No warranty

9. Starrett 449AZ-3R Vernier Depth Gauge Micrometer

Moving on to the next one, we have the Starrett 449AZ-3R Vernier Depth Gauge which comes with a resolution of 0.001 mm and a range of 3 inches. You get a ⅛ inch long and 1/64 inch wide blade that is ideal for taking measurements of very narrow holes with accuracy. The baes are hardened, ground and lapped to make them sturdier. You also get a protective case in the package.

buy now!

Pros:

  • High Accuracy
  • Quick to adjust
  • Ideal for narrow spaces

Cons:

  • No digital display unit

10. Mitutoyo 128-105 Vernier Depth Gauge Micrometer

Lastly, we have the Mitutoyo 128-105 which offers a resolution of 0.001 mm and range of 1 inch. You get a single rod with it with a diameter of 0.175 inches. You also get a ratchet stop on it for uniform pressure and a rod clamp that gives it extra stability. The base of this depth micrometer is 2.5 inches long. You also get a satin chrome finish on this micrometer to prevent glare and take the readings easily.

buy now!

Pros:

  • Comes with ratchet stop and rod clamp
  • Ideal for smaller holes and bores
  • High accuracy

Cons:

  • The measuring range is short

Things To Consider Before Buying A Depth Micrometer

1. Type

When it comes to the type, you will see two types of depth micrometers in the market that are the analog depth micrometers and the digital depth micrometers. The analog ones are very accurate and easy to use but if you are someone who finds it very hard to be really careful and slowly take readings then you should go for digital type as they are very easy to read and you don’t have to go for the whole calculations process after taking the readings.

Which Is Better Between A Mechanical or Digital Depth Micrometer?

So, which model is your favorite? Each model has its own pros & cons. In conclusion, the mechanical model is a suitable option for occasional use.

Meanwhile, if you need speed, the digital depth micrometer is excellent.

For ease of measurement, especially if you will occasionally take readings with your micrometer only, we recommend a digital model.

Unfortunately, its price is quite high. So, choosing the model of depth micrometer should depend on your need and budget.

By recognizing and comparing the advantages & disadvantages of each mode, you must have the idea of which one is better for you.

Hopefully, this guide will be useful, especially for those who want to know how to read depth micrometer.

2. Accuracy

The use of a depth micrometer entirely relies on the accuracy that it provides. If it is not very precise then you will not get precise results and this might end up in causing major failures. To avoid that, always check the accuracy of the micrometer before buying it so you don’t have to encounter such issues.

3. Number of Measuring Rods (Measuring Range)

Along with most of the depth micrometers, you will get more than one measuring rod. All of them have different sizes. Depending on the use of the depth micrometer and your requirements, you can choose how many measuring rods you need with it. Also consider the size of the rod provided with it while getting a depth micrometer.

Depth Micrometer Accessories

Besides depth micrometer parts, it is also important to know about depth micrometer accessories.

1. Depth Micrometer Base Extension

You should mount it flush with a depth micrometer base. So, you can position the micrometer safely across a large opening or bore.

Using it will provide a depth reading without requiring to balance a base which doesn’t extend all the way.

You use this extension with a depth micrometer to measure hard-to-reach or large features or bores.

2. A Set of Micrometer Anvils and Tips

You can use micrometer anvils and tips to replace damaged anvils on a depth micrometer.

Besides that, they allow you to customize your instruments for specialty applications.

3. Micrometer Battery Cover and Replacement Parts

You may often break or lose a micrometer battery cover. Now, you can keep your depth micrometer safe & secure & its battery in place with this battery cover.

4. Micrometer Calibrating Standards and Sets

These are precision ground rods of different lengths that come with fixed dimensions to determine whether the depth micrometer is accurate.

In order to calibrate a dept micrometer, you should actuate the thimble & use the standard as the object being measured.

So, it confirms that the digital or vernier reading matches the standard’s exact dimension.

5. Micrometer Setting Rings

They are round & smooth precision-formed rings that come with fixed dimensions measured with a depth micrometer to check that the micrometer reads correctly.

So, that’s all about depth micrometer parts you will need to know. By knowing about each part, you will be able to use and care for it rightly.

Depth Micrometer Uses

When it comes to depth micrometer uses, you have to know that you use it to measure the depth of recessed areas, slots, and holes.

Besides that, it comes with a measuring face (base) on the barrel or sleeve. In addition, it has a spindle attached with thimble.

Then, the spindle axial movement takes place by the thimble rotation.

If you want to make measurement with a depth micrometer, it should be between the spindle’s end face and the base face.

When the spindle is moving away from the base, the measurement is increasing because the scales on the sleeve are reversed from the normal.

After you know about depth micrometer parts, you have to know that the scale indicates 0 when the spindle flushes with the face & maximum when the spindle is extended fully from the base.

For your information, the main scale reading is 17. Then, the thimble’s 14th division line matches with the reference line.

When it comes to depth micrometer range, it is available in ranges 0-25mm or 0-50mm. However, you can increase the range up to 0-90mm with extension rods in steps of 25mm.

You can insert the extension rod easily. In this case, you just need to remove the spindle cap.

How to Calibrate a 0-1” Dept Micrometer

After you know how to use depth micrometer, we will talk about how to calibrate a 0-1” one.

  1. Verify Its Cleanliness – Make sure that the depth mic is clean.
  2. Examine It Visually – You also need to visually examine the depth mic for any condition that can cause errors or issues in the calibration.
  3. Check the Internal Condition – Sometimes, it needs to disassemble for adjustment to make sure that there’s no damage to the internal threads of the depth mic.
  4. Check the Depth Rod – You may need to spin the thimble until you find that the depth rod is inside the depth micrometer.
  5. Make the Depth Rod to the Zero Position – Place it on a surface plate & spin the thimble in order to extend the depth rod so that it is on the zero position. If available, you can use the friction stop or ratchet.
  6. Repeat the Process – Now, repeat the process. It means, you should place the depth mic on gage blocks & overhanging it to allow the depth rod to extend down to the surface plate.
  7. Check Accuracy – Then, check its accuracy at different locations within the measuring range of the tool. For this operation, you should use gage blocks that have been calibrated. Besides that, block sizes should test the depth mic at various positions of the thimble, not increments of .025” only to ensure that the scale on the thimble is really accurate. At this step, you can make adjustments if needed. However, different types of depth mics may have different adjustment procedures.

So, that’s all how to use depth micrometer. If you want to make adjustments on your depth mic, you can consult manufacturer for instructions.

Read further about micrometer calibration (outside, inside, and depth micrometers) here.

F.A.Q.

Q: How to check the accuracy of a depth micrometer?

A: To check its accuracy, you can inspect or calibrate a depth micrometer by a set of gauge blocks. That means, you check several depths. Make sure that the gauge blocks are calibrated as well so that you are comparing with accurate gauge blocks as well.

Q: How to take care of depth micrometer?

A: Things such as wiping the mic before using, regular oiling, storing it in correct temperature and humidity, battery removal during long storage, regular calibration, stored in a good case, etc are some micrometer maintenance practices you can do to keep this precision measuring tool long last.

Conclusion

We gave you a brief idea about its use along with the comprehensive reviews of the top ten depth micrometers. We hope you found this guide really helpful and you can now easily choose a depth micrometer for yourself. If you are still not sure about which one to buy then we have some recommendations for you.

As the best choice overall, we would recommend the Starrett 440Z-6L Vernier Depth Gauge as it is very accurate, comes with multiple measuring rods and a hardened base ground which makes it sturdy. If you are in search of a digital depth micrometer that can help you get the depth readings quickly then we would recommend the Brown & Sharpe TESA 60.30069 Digital Micrometer Depth Gauge as an affordable option you should choose the Accusize Industrial Tools 2025-4201 Depth Micrometer. It comes with a satin chrome finish, and is very accurate as well.