Beginner’s Guide to Micrometers – Get Started

a 0-1" outside micrometer
A standard outside measuring micrometer

What is a micrometer?

A micrometer is a precision measuring tool. 

They are used in manufacturing, machine shops, automotive work and the construction industry. 

“Mic” is shorthand for micrometer.

Mics are very accurate measuring devices. 

Micrometers are used to take measurements with an accuracy of ~.0001″ or better in inches. 

Measurements in millimeters can be made down to .01mm or .001mm.


How accurate are micrometers?

Most micrometers have an accuracy of +/- 0.0001″, commonly referred to as a tenth of an inch in machining.

The standard metric versions would come as +/- 0.001mm or +/- 0.002mm.

They can be found with worse or better accuracy but what is usually seen .

When to use a micrometer

Three of the most common precision measuring devices used by a hobbyist or a machine shop are calipers, micrometers and dial test indicators. 

Calipers have the least accuracy of the three and the largest measuring range.

a mitutoyo digital caliper with the display on
Mitutoyo digital caliper

The dial test indicator has the most accuracy and least measuring range. 

Micrometers are in the middle for both accuracy and measuring range. 

While still very accurate, one downfall of the micrometer is that they usually come with a 1″ measuring range (3-4″, 4-5″, etc.).

Because of this they are often sold in sets to cover a larger measuring range. 

A 0-6″ micrometer set will cover the needs of most applications while a 0-12″ set is more than most people, especially hobbyists will need. 0-3″ sets are also common.

Parts of a micrometer

a micrometer with all of its part identified

How to use a micrometer

Before using your micrometer, ensure that the measuring tool and surface to be measured are free of dirt, debris, chips, etc.

Everything should be clean.

The micrometer thimble should spin freely. No hangs up or anything similar.

a micrometer with the thimble identified

Open the thimble to place the part you want to measure between the anvil and spindle.

Spin the thimble until it closes on the part. 

You aren’t trying to clamp down on the part. 

closeup of a micrometer with the ratchet stop identified

Use a gentle, consistent amount of force when spinning the thimble. Using the ratchet on your micrometer can make this easier. Try spinning the thimble until you get three clicks on your ratchet.

This will help you get repeatable measurements. You want to be consistent in your measuring so you know your readings are good.

This is why taking multiple measurements is so important.

When possible, measure the part multiple times to be confident your readings are accurate.

A little practice on a cheap gauge block can help here. Measure that same gauge block a bunch of times and you will become more repeatable in your measurements. You’ll also see how easy it is to change your reading.

a micrometer with the anvil and spindle identified

As the spindle closes on the part being measured, it can be beneficial to slightly rock the micrometer in an effort to seat the micrometer on the part.

Be careful: this technique isn’t right for surfaces that could be scratched or damaged easily.

Once you have closed the part in the micrometer, it is time to take your measurement reading.

How to read a micrometer

The most common variety of micrometers measures to one ten-thousandth of an inch (.0001″).

Measurements are taken by identifying where the lines on the micrometer line up.

You will need to take 4 readings and add them together to get your measurement.

These readings are the 0.1000″, 0.0250″, 0.0010″ and 0.0001″ readings.

Machinists refer to these as the hundred thousandths, 25 thousandths, 1 thousandths and lastly the tenths readings.

Let’s get started.

Along the sleeve of the micrometer will be graduations similar to a ruler. The graduations at every fourth interval are most often numbered 0, 1, 2 and so on. 

These numbers represent .100″ or one hundred thousandths of an inch. 

closeup of a micrometer with the 0.100" graduations identified

Whichever hundred thousandths reading you are past is your reading. In the pic above, the hundred thousandths reading would be 3 which equals 0.3000″.

Once you have taken your hundred thousandths reading then you will need to take the 25 thousandths reading.

Each mark along the sleeve is 0.025″ or 25 thousandths.

closeup of a micrometer with the 0.0250" graduations identified

Next is the reading from the thimble. This is the 0.0010″ reading or one thousandth of an inch reading. 

In the pic above two lines are shown past the three so the 0.0250″ graduation value would be 0.0500″.

In the end we are going to add all of our individual measurements up for our final reading.

closeup of a micrometer with the 0.0010" graduations identified

Note the 0.0010″ reading on the thimble and lastly take the tenths reading from the spindle.

Here we have 15 thousandths.

This makes our measurement so far 0.300″ + 0.0500″ + 0.015″ = 0.3650″.

closeup of a micrometer with the 0.0001" graduations identified

The last reading to take is the tenths reading. If the lines matched up at the 6 tenths mark, then we would have a reading of 0.0006″ which we need to add to our previous readings.

0.3650″ + 0.0006″ = 0.3656″ or three hundred and sixty five thousandths of an inch and six tenths.

Frequently asked questions about micrometers

What kinds of micrometers are available?

There are a ton of different micrometer types available

Often specific industries have their own special type micrometers such as the auto related micrometers on our list of the most common micrometers below:

  • Outside micrometers – measures various lengths, widths, thicknesses and diameters
  • Inside micrometers – measures hole diameters, slot widths
  • Depth micrometer – measures depth of holes, step locations
  • Thread micrometers – measures various thread characteristics
  • Crankshaft micrometer – specific measuring range for measuring crankshafts
  • Disc brake micrometer – measures thickness of brake rotors
  • Blade micrometer – measures slots, keyways and grooves

Are cheaper micrometers as good as expensive ones?

The cheaper off-brand micrometers have gotten much better in recent year, but they haven’t quite caught up to the best manufacturers yet. 

Starrett and Mitutoyo still reign supreme in terms of quality and accuracy.

You can always look for used options on Craigslist or Facebook marketplace to save a buck.

What makes a good micrometer?

A good micrometer needs two things: precision and accuracy. 

Some adjustments can be made with most micrometers to account for small errors in accuracy but nothing can be done to fix a tool that isn’t precise. 

Quality micrometers will turn smoothly without any drag. This is the telltale sign of a good tool. If your micrometer ever feels like it is rubbing internally, we recommend disassembling the micrometer and cleaning per the manufacturers instructions to eliminate any possible contamination that may be causing the issue

How to adjust a micrometer

If your micrometer is in need of adjustment, most micrometers can be adjusted by using the wrench that came with your tool to spin the sleeve of the micrometer. This is usually done in the zero position. This can be especially useful for adjusting for the touch or feel of a mic when it does not include a ratchet or friction stop. 

If you no longer have a wrench or spanner for adjustment, replacement wrenches can be purchased from most manufacturers or on Amazon.

How often should my micrometer be calibrated?

How often you need to calibrate your micrometer will vary depending on a few factors such as what you are measuring with it, how often you are using it, and what type of environment it is in.

Check out our guide to micrometer calibration to get a better understanding of the how, where, when and why of calibrating your mics.

Micrometers and Calipers [Similarities, Differences & Everything Else]

micrometers vs calipers

Micrometers and calipers are both precision measuring tools.

The difference between these tools lies in their accuracy and the types of measurements they can take.

Check out the table below for the main differences between the two tools and then keep on reading to gain a better understanding of what those differences mean when it comes time to use them.






Measuring Range

1" increments


Types of Measurements

Outside Measurements

Inside, Outside & Depth Measurements

Micrometer and caliper comparisons


Micrometers are more accurate. 

A typical micrometer is accurate to 0.0001″ and a caliper is only accurate to 0.001″.

This makes a micrometer 10x more accurate than a caliper.

Just keep in mind that you can buy cheap versions of both tools that have worse accuracy. Also, if you were to buy a larger versions of these tools they will often have lower accuracy. 

A 17-18″ micrometer might only be accurate to +/- 0.0002″ and a 0-24″ caliper may only be accurate to +/- 0.002″.

To sum it up, realize that there is some variation in accuracy but in general you will find that micrometers are 10x more accurate than calipers.

Measuring range

starrett micrometer set in case with reference standards

Micrometers come with 1″ measuring ranges. 0-1″, 1-2″, 2-3″ and so on. 

The most common measuring calipers measure over a 0-6″ range. Larger varieties can be also be found with 0-12″ and 0-24″ measuring ranges. There are some different ranges available such as 0-4″ and 0-8″ also but they are much less common.

This difference in measuring ranges means that you would need a set of micrometers to measure over the same measuring range a single caliper is capable of. 

Calipers have larger measuring ranges but they are less accurate.

Types of measurements they are capable of

Caliper measuring internal hole
caliper depth base attachment
Depth measuring rod extended from caliper - depth base attachment shown

Most calipers will measure inside, outside and depth measurements. 

digital caliper measuring coin
Standard outside diameter being measure with digital caliper

Micrometers are capable of only performing one type of measurement. 

The most common type of micrometer is an outside micrometer, usually referred to as simply micrometers or sometimes mics.

anytime tools 1-2" micrometer

Inside micrometers and depth micrometers are also available to take internal and depth  measurements.

Calipers are capable of taking a much larger variety of measurements.

Depth micrometer with multiple rods for different size measurements
mitutoyo inside micrometer set
Inside micrometer with multiple attachements for different size measurements

Ease of use

To maintain the added accuracy that a micrometer has requires taking more care when using them. 

Something as small as the amount of force you use to close the micrometer can change your measurement. Many micrometers will have a ratchet or friction stops that help alleviate this problem. 

When you are working down to a tenth (machinist lingo for 0.0001″), even temperature comes into play. Metals expand and contract with changes in temperature. To protect against this, most micrometers have plastic pieces that can be used to help insulate your from the tool.

outside micrometer

A good micrometer stand can help keep you accurate as well.

The same factors affect the accuracy of a caliper but the effects aren’t as noticeable because they aren’t as accurate.


Calipers are quicker to use than micrometers. The jaws can open and close in a split second.

Micrometers need to spin the thimble around 40 times to cover an inch of travel. 

Cost comparison

A micrometer and a set of calipers have similar price points. Take for example a 0-1″ micrometer from Mitutoyo and a 0-6″ set of calipers from Mitutoyo.

The difference would be that to cover the same measuring range of a set of calipers, you would need a 0-6″ set of micrometers. A good set of micrometers is going to cost quite a bit more than your typical 0-6″ caliper.

More info about micrometers and calipers

Parts of a micrometer

parts of a micrometer

The part being measured will be placed between the anvil and spindle of the micrometer. The spindle is adjusted in and out by turning the thimble clockwise or counterclockwise. 

Depending on the micrometer being used, the lock nut, lock ring or lock lever can be used to hold the micrometer at a specific size. Some tools will not have any locking feature. 

Measurements are read using the scales on the sleeve and thimble. 

The frame of the micrometer can vary across brands and types of micrometers. Some are made specifically to have smaller frames for different measuring applications. 

Many micrometers also have a ratchet stop or friction stop that limits the amount of force applied to the thimble. This allows more consistent measurements.

Parts of a caliper

The jaws for external measurements are used to measure features such as length, width and thickness.

The jaws for internal measurement are used for measuring features such as hole sizes and slot or groove widths.

The rod for depth measurements is used for measuring depths of holes, counterbores and step heights. 

The scale and dial indicator face are used together to obtain measurement readings.

The slide of the caliper which consists of the moveable jaws along with the dial indicator face are slid along the beam.

The lock screw can be used to hold the caliper at a specific size for repetitive measurements.

Digital vs analog micrometers

Digital micrometers are great for the speed at which measurements can be read. Their display means very little training for the operator. 

Another benefit of a digital micrometer is how quickly measurement values can be converted between inch and metric readings. A simple button press can save time and do the conversion for you. 

starrett 0-1" micrometer
Starrett analog micrometer
mitutoyo digital micrometer
Mitutoyo digital micrometer

The downfall is that they tend to be quite a bit more expensive than a standard analog micrometer and they are more susceptible to contaminants such as water and coolant. Some models are offered with resistance or protection from different contaminants. 

In recent years, prices have dropped for digital micrometers making them more affordable. 

Analog micrometers tend to be a very dependable tool and many have been in use for generations. This also means that there are many used options on the market for analog micrometers. 

If cost is your primary concern, I recommend going with an analog micrometer. If ease of use and operation is important then go with a digital micrometer.

Digital vs dial vs vernier calipers

mitutoyo 6 inch vernier caliper
Mitutoyo vernier caliper

Vernier calipers are the most resilient type of calipers. They will be the least affected by things such as dirt and water or coolant. Unfortunately they are the most difficult to take measurements with. Learning to read the scales takes some practice. 

Dial calipers are a good middle ground with measurements that are relatively easy to take with the dial indicator face. They are reasonably resistant to contamination though they should still be handled with care. 

anytime tools dial caliper dial face
Dial caliper

Digital calipers are by far the easiest to use. The LCD display takes any guesswork out of reading your measurement. They are also the most susceptible to damage from things such as dirt and coolant. 

Unless they are being used in the harshest environment, I recommend getting digital calipers. Digital calipers can be purchased with ingress protection if needed.


While they are both precision measuring tools, there are some key differences between micrometers and calipers. 

Micrometers are more specialized and have a smaller measuring range. As a result they are generally more accurate and often capable of measurements to .0001″. 

Calipers are more versatile. They have a much larger measuring range. To achieve this they sacrifice accuracy and most often take measurements to an accuracy of .001″. 

As you can see they both have their strengths and weaknesses but in the end they are two of the most important precision measuring tools you can have in your toolbox.

Best Micrometer Stands

Micrometer stands are simple devices that serve a very important purpose. They give you a hand and no, I do not mean complement your super awesome machining skills.

They work to free up a hand that would otherwise be used to hold a part or measuring tool. Their most frequent application is to hold micrometers for use in high volume manufacturing. In addition to this, they are often used by hobbyists and home machinists in their pastime pursuits.   

These simple tools should be easy to get right….right? See our very short list of the best micrometer stands to find out.

Best overall micrometer stand

Grizzly Industrial G5727 - Micrometer Stand

Grizzly Industrial makes some very good tools for their price. Their tools are made in Taiwan and China, but the company is based in America.

They have quality control personnel at the manufacturing facilities to inspect the tools before shipping them stateside. This is likely the key to how they have been able to provide good tools at a reasonable price.

This micrometer stand from Grizzly is a solid piece of equipment. It is solid, heavy and clamps well without issue. There have been some reports that occasionally the stand doesn’t operate as smoothly as expected but most report that a little oil fixes it up quick.

Overall, the Grizzly stand easily beats out the straight from China copycat competitors and does it while keeping the cost much lower than the premium tool manufacturers.

Honorable mentions

Mitutoyo 156-101-10 Micrometer Stand

Best of the best but at a price.

It should be no surprise that Mitutoyo makes our list of the best micrometer stands. They make excellent micrometers as well as other dimensional measurement equipment. Across the board they make excellent tools and gauges. The only downfall of this is that their quality comes at a price.

When it comes to measurement equipment such as micrometers, calipers and indicators, the quality is worth the price.

When it comes to simple tools, the nicer stuff just isn’t worth the price.

The Mitutoyo micrometer stand is a nicely finished, version of exactly what it should be. It’s a clamp with a solid base to keep things steady.

While simple in design, it does exactly what it sets out to do. And it does it consistently. Tools like this will last multiple lifetimes if not treated right. Yet it still doesn’t justify the price.

If budget is of no concern, then go with the stand from Mitutoyo. For everyone else, think about going with one of our other picks for a slight downgrade in quality and a big difference in price.

Accusize Industrial Tools S907-C153 Micrometer Stand

A nice budget friendly option.

The Accusize micrometer stand has a solid base which provides good stability and non-slip feet to make sure it stays right where you want it without the need for clamping it to your workbench. However, it can still be clamped if you want 100% assurance that this puppy won’t move.

It should be obvious from the photo, but it isn’t as heavy or big as our other options, so it loses a little in stability. It makes up for it though with its small, almost portable size. 

This stand from Accusize folds flat allowing it to be stashed away easily when not in use. A welcome feature for those of us with cluttered workbenches.

The S907-C153 isn’t the end all, be all of micrometer stands but for the price it certainly does a respectable job of keeping your tool in place.

Frequently asked questions

What is a micrometer stand?

outside micrometer

A micrometer stand is a tool used for holding measuring equipment and various objects for precision work. The angle of the stand can be rotated to find the best position for working.

The heavy base of the stand keeps things steady. In addition, the stand can be clamped to a table or workbench to provide more stability.

How do you use a micrometer stand?

Micrometer stands are pretty simple. Basically, it is a two-way clamp.

There is a clamp for holding the tool in place, as well as a clamp for rotating the holder and adjusting the angle. Once clamped, the base steadies the object while allowing the user to keep two hands free. They also have the added benefit of insulating the object being held to varying degrees of heat.

Why would you use a micrometer stand?

A micrometer stand will allow you to free up your hands for precision work such as soldering PCBs or measuring tight tolerances, especially in high volume.

Another benefit is limiting the amount of heat transfer from the user, to either the object they are measuring or to the measuring device itself.

Thermal expansion will cause things to expand. This isn’t a good thing when trying to take measurements down to very tight tolerances.

A good micrometer stand will help insulate your tools from your body heat and give you more accurate readings.

Related articles

For more information check out these related articles:

Best Micrometer Sets for Machinists and Hobbyists

Not many tools get as much inspection use as a micrometer. As a result, the first inspection tool purchased by many is a good micrometer or a micrometer set. 

Because of their expense, they are not tools that you will want to buy more than once. The good thing is that if chosen carefully, they will last a lifetime or more. As the saying goes, “buy once, cry once”. 

Now take a look at the best micrometer sets available, many of which have been best in class for many, many years.

Best micrometer set

Starrett ST436.1CXRLZ 0-6" Outside Micrometer Set

When it comes to the standard analog micrometers, nobody makes them like Starrett. The most important aspect of a micrometer is its accuracy and these mics by Starrett are extremely accurate and repeatable.

As long as you exercise due care in your measurements, you can expect them to be accurate to .0001”. While it is true that many other manufacturers have been able to create a tool that is capable of the same accuracy, few come close to the build quality of a Starrett micrometer.

It can be hard to quantify the “feel” of a tool. In this case, these mics just feel right. The weight is nice without being too heavy. More importantly, they have a nice balance to them that never seems to get in the way of your measurement.


The finish of both the frame of the micrometer as well as the sleeve has always been excellent. The knurling on the thimble and ratchet provides the perfect amount of grip.

Speaking of the ratchet, I have always found that Starrett makes the best ratchets. Ratchet preferences can vary from person to person but the thing that is nice about these ratchets is they are extremely consistent. Between mics in a set, the ratchets will all feel the same.

Starrett has been making these same micrometers for quite some time and largely without change. If it ain’t broke, don’t fix it.

The one downfall of these micrometers is that the quality does come with a price. For this reason, I have included a second choice in the Mitutoyo set below. It can also be worth considering the best digital micrometer set if you need more accuracy and can live with a smaller measuring range.

Used versions of these tools can be an excellent choice also because all of the choices noted here, from both Starrett and Mitutoyo, have a long history of being quality measuring tools. They have been mostly unchanged through the past couple decades.

As a side note, the case that comes as part of the set is as well made as the micrometers themselves.

Mitutoyo 0-6" Outside Micrometer Set

This set of micrometers form Mitutoyo checks all the boxes. They are accurate, consistently well-made and reliable. They are only a small step below the set by Starrett. While they might not be the absolute best micrometer set available, they might be the best value because the price is substantially lower than that of the Starrett set.

For comparisons sake, if the micrometer set from Starrett is a Rolls Royce, then the set by Mitutoyo is a Cadillac. This is certainly reflected in the price difference.

The main difference between the sets is in the feel of the mics. The finish of the Mitutoyo set is nice, but not on the same level as that of the Starrett set. Also, I have always found the ratchet mechanism and balance of the mics by Mitutoyo to be very good but not as great as the Starretts.

I feel like this might sound like the Mitutoyo set is not that great but in reality, they are excellent. They just aren’t quite as good as the Starretts. However, they are much better than all the other micrometers out there and they come with a much smaller price tag.

Best digital micrometer set

Mitutoyo 293-961-30 Digimatic Micrometer 0-4”

I absolutely love the Mitutoyo Digimatic micrometers. They are easily the most accurate normal micrometers out there. Sure, you can find specialty mics with indicators built in that will be more accurate, but they will be more expensive and less user friendly.

If given the choice, I would use Mitutoyo Digimatic mics for all micrometer measurements. They are quick to read and extremely accurate.

The only knock I could give them is that some might find them a little bulky. Personally, I have never found this to be the case, but they are larger than your average analog mic.

Digital micrometers also make a great choice when working in both inch and metric units. The ease with which they switch measuring units saves time and eliminates any potential conversion miscalculations that might occur by the user.

Another great feature of the Digimatic mics that is not common among other digital micrometers is that the batteries seemingly last forever. No, not literally but even with heavy use it feels like it.

The sole reason they didn’t make the best overall micrometer set is that the set includes less micrometers and is limited to measuring sizes up to 4”. If this isn’t a problem for your applications then think about taking a good, hard look at the Mitutoyo Digimatic mic set. They are an absolute top of the line set.

Best budget micrometer set

Anytime Tools 0-6” Outside Micrometer Set

In recent years, some of the Chinese made micrometer manufacturers have greatly increased their quality. Anytime Tools is a prime example of this. They have been able to create tools for a fraction of the price of a traditional micrometer while largely maintaining the accuracy and quality seen with more well-known manufacturers.

The improvement in Chinese made micrometers is so great that some American tool manufacturers have been outsourcing their tools to other countries.

With regards to accuracy, they claim to be accurate to .0001” as you would expect from a good micrometer. In practice, they aren’t quite there all the time. It would be safe to count on .0002” accuracy. If you are looking for more than that then make sure to verify the accuracy when you receive them.

The Anytime Tools set comes with all the standard micrometer set accessories including reference standards for verifying their accuracy and a wooden case. The case isn’t as nice as what comes with more expensive sets, but it is just a box after all. It holds all of the included mics and closes to keep out the elements. It makes a perfectly acceptable storage solution.

The feel of this set isn’t quite as nice as those from Mitutoyo and Starrett but the reduction in price can not be overlooked. This set could be purchased along with a set of gage blocks to verify their accuracy and the price tag would still be well under the cost of other quality sets.

I would never recommend going cheap when it comes to your precision measuring tools if they are critical to your job. The one exception is, if you are a hobbyist or just entering the machining trade, this micrometer set from Anytime Tools makes a great starter set that just might meet all of your current and possibly future measurement needs.

Things to consider when purchasing a micrometer set

How big of a set to get

It all comes down to the sizes you plan to measure. Usually, the required measurements are skewed towards the lower end of the measuring scale. A 0-1” micrometer will be the size used most often. The 1-2” micrometer will be the 2nd most used micrometer and so on.

As the sizes get larger, they will see substantially less usage. Even in a high use environment such as a machine shop, a 5-6” micrometer or 11-12” micrometer will rarely be used.

My recommendation would be to not buy a larger set than you need. A good micrometer set is not cheap and therefore you should ensure the tools will get used. You don’t want a box full of expensive paperweights.

Unless you know that you absolutely need it, I would never recommend purchasing a set larger than 12”. A 0-6” set makes a good starting point for most people and if you think you can get away with something slightly smaller then go for it.

It is better to buy a higher quality 0-3” set than it would be to have a 0-6” set where the 4-6” mics never get used.


Accuracy and repeatability are the most important qualities in a micrometer. It is possible to find a wide variety of accuracies available in micrometer, especially when it comes to older used tools.

You should look to get a micrometer with an accuracy of .0001” or better. I have included a cheaper, slightly less accurate budget set above, but you should only go with that set if price is your primary concern and you know that the reduction in accuracy is acceptable for your measurements.

I have never known anyone to regret purchasing a more accurate tool.

Analog vs mechanical counter vs digital

Each type of micrometer has its pros and cons.

Analog mics are always ready to go. You never need to worry about dead batteries and aren’t quite as susceptible to contamination (coolant, etc.) when compared to digital micrometers.

Digital micrometers are easier to read, quicker to take measurements and allow the user to easily switch between measurement units. Additionally, they allow the user to switch their zero location at will. There are many instances were comparison measurements need to be taken. Digital micrometers allow these types of measurement to be taken quickly without the added need for manual calculations.

mitutoyo mechanical counter micrometer
Mechanical counter micrometer

I do not recommend the mechanical counter micrometers. They add another mechanism that can malfunction simply don’t provide enough of an added benefit to justify their use. Electronic digital micrometers can be found for the same price as the mechanical counter versions.

Go with a standard analog micrometer or a solid digital version and skip the  prone mechanical counter varieties.


Cases are all about protection. You don’t need anything too fancy when it comes to cases. The standard wooden case that comes with most micrometer sets is more than capable of storing your tools.

The case gives the tools a place to stay with protection from the elements (there can be a lot in the air when machining) and also a safe storage option. Too often a micrometer left on a workbench gets bumped and ends up hitting the floor.

Keep your tools safe and make sure to put them away when not in use so they remain accurate for years to come.

Carbide vs steel tips

Steel tips
Carbide tips

Carbide tipped micrometers provide increased wear resistance. In general, I have not found them to provide an added benefit to hardened steel.

Please note that carbide can be more brittle as a result of the added toughness which means they are susceptible to chipped measuring faces. If cared for properly, this will likely not be an issue, but it is something to keep in mind.

The main case for carbide tips would be when dealing with particularly abrasive materials.

For most users, both carbide and steel tipped micrometers will be more than adequate.

Calibrated or not

There are manufacturers and sellers out there who offer calibrated micrometers for an added cost. This is not an item that is worth paying extra for.

The micrometers should be made accurate from the start. Calibration only gets you documented evidence that your tool is verified as accurate using a reference standard that is traceable to NIST. If this is something you require then you likely already have a set of calibrated gage blocks that will allow you to do the calibration on your own.

Shipping companies are not always gentle with your packages so keep in mind that it would be entirely possible to pay extra for calibration and have the calibration voided by shock from shipping.

Skip the calibration upcharge and verify your micrometers on your own.


Choosing a micrometer set is not an easy decision. Even the cheapest options cost a pretty penny. The most important things to consider is the accuracy you need as well the size of the set you require.

If they will be used daily, don’t be afraid to splurge and pick up a heirloom quality set from Starrett or Mitutoyo. They really are worth it and built to last. 

Related articles

For more information check out these related articles:

Ultimate Guide to Micrometer Calibration

Outside micrometers are easily one of the most common measuring tools in the machinist’s toolbox. They are so common that they are usually referred to as simply micrometers or mics. For the rest of this post, I will follow the same convention.

A side note, specialty micrometers such as depth micrometers or inside micrometers are more often referred to by their whole name.

Now that you are on a first name basis with your micrometer, let’s think about calibrating it.

So just how important is it to have a properly calibrated micrometer?


outside micrometer

Considering a 0-1” micrometer is likely the most used inspection tool in the shop… pretty darn important.

Please note that some of what follows might be overkill for a hobbyist but it is certainly still good practice.

Now, let’s learn more about micrometer calibration.

Why do micrometers need to be calibrated?

Micrometers need to be calibrated to ensure their accuracy.

Because they are used for critical measurements, it is important to make sure that any readings taken with the micrometer are correct.

During the calibration process, the micrometer is checked with a standard, such as a gauge block, to verify it is accurate across its entire measuring range.

How often should you calibrate a micrometer?

There are many factors to consider when determining how often to calibrate your micrometer. The visual below lists some of the most common factors.

Micrometers can be calibrated at many different intervals. When setting the calibration frequency, you should take into account factors such as:

  • How the tool will be used? Is the micrometer being used to measure critical product dimensions?
  • How tight are the tolerances it will be used to measure?
  • Will it be subjected to stresses such as heat, humidity, pressure, physical stress or other environmental?
  • How much usage will it see?
  • What is the tool’s past calibration history?

Where I work we take all of these factors into account and develop our calibration intervals based on them. We group tools into different intervals.

The most important tools are calibrated every four months or sooner. Less critical tools are calibrated on a yearly schedule. Occasionally, tools which see little use and have an excellent calibration history get calibrated at a more extended interval.

It all depends on what works for your shop. If you are unsure of where to start, calibrate more frequently and then adjust based on usage and calibration history over time.

Think about all of these factors when determining how often you will calibrate your micrometer.

What equipment do you need to calibrate a micrometer?

Calibration of your micrometer requires only a known length standard such as a gauge block, an adjustment spanner and your micrometer.

Additional supplies such as gage oil and task wipers will also come in handy but aren’t required.


gauge block set
Gauge block set

Gauge blocks should be chosen that are at a minimum four times more accurate than your micrometer.

If your micrometer reads to a tenth (.0001”) like most common micrometers, then you will need gauge blocks that are accurate to 25 millionths of an inch (.000025”).

This 4:1 requirement started with the military specification, or mil spec MIL-STD-45662. This specification defined the calibration requirements for companies.

This requirement is a minimum requirement. Using gauge blocks that are 10 times more accurate than the micrometer is even better.

length standards set
Length standard set

Note: For larger micrometers, length standards are often used in place of gage blocks.

Do I need to buy a micrometer that is already calibrated?

No, buying a micrometer that is already calibrated is not required.

In fact, I recommend not purchasing a micrometer that comes with a calibration certificate. The certification process costs extra and adds no extra value.

You will want to check the calibration of the tool once you get it anyways. Shipping companies aren’t always gentle and just because it was in calibration at the time of shipping does not ensure it is in calibration when received.

What do I need to maintain for calibration records?

At a minimum, your records should include calibration labels for your tools and a database where you record calibration information.

Free and printable calibration labels are available on our calibration labels page. All types of stickers are included for everything from tool calibration labels to do not use labels.

What information should the calibration label include?

Calibration labels should include at least the calibration date along with the next calibration due date. It is also a good idea to include the person who calibrated the tool and the tool #.

Note: It is acceptable to place a label on the box of a measuring tool if it isn’t practical to place on the tool such as is the case with a set of gauge blocks.

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Example calibration label

What information should be included in the calibration database?

The calibration database can come in many forms. Card systems, spreadsheets, database files and specialty programs are often used to maintain calibration records.

The following information should be recorded in the calibration database:

  • Who performed the calibration
  • Date calibration was performed
  • Master standard that was used for calibration
  • Calibration checks to be performed
  • Acceptable limits for calibration checks
  • Actual readings from the calibration checks
  • Next calibration due date

While it isn’t always a strict requirement, it is a good idea to think about recording the environmental conditions such as temperature and humidity when performing your calibration.

Example calibration procedure for a micrometer

  1. Read the entire procedure before beginning calibration
  2. If at any time in the calibration procedure a problem is identified, the problem will be corrected and the process will start over. If the problem can not be fixed, the micrometer will be taken out of service.
  3. Clean anvil and spindle faces along with all exterior surfaces.
  4. Inspect the micrometer for any damage or issues which might prevent accurate calibration.
  5. Close the micrometer using ratchet or friction stop if present.
  6. Hold the micrometer up to light and visually examine. If faces are not parallel, light will show between them. There should be no light visible between the faces of the anvil and spindle.
  7. Remove the spindle assembly.
  8. Clean and oil spindle and measuring screw.
  9. Reassemble the micrometer.
  10. Check measuring screw for wear by pushing thimble in and out. Do this in the direction of the measuring screw axis. There should be no movement.
  11. Close the micrometer by using the ratchet or friction stop if present to check the zero setting.
  12. Check accuracy with gage block(s) having accuracy not less than 0.000025 inch. Verify measurements at sizes that are not even intervals. Use sizes such as .206”, .456” or .784”. Avoid common sizes such as .250”, .500” and .800”. Verifying sizes that are not even increments of .025” will verify the scale around the micrometer.
  13. Place block or block combinations between anvil and spindle of the micrometer and close the micrometer using ratchet or friction stop if present. Use block combinations to check the accuracy of the instrument positions across the total measuring range.
  14. Record all above readings in the calibration database.

Steps 8 and 9 are not required but are good preventative maintenance for your tool.

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Best Micrometer Brands – New, Used and Everything In Between

Micrometers are incredibly accurate measuring tools. They get used for the most demanding measurements from engine work to reloading. Measurements that critical require tools that will ensure your project is done right.

When it comes to micrometers, the best manufacturers are the ones that consistently put out a quality product. These are those brands:

Best micrometer brand


Starrett has been in the micrometer business for a very long time. It’s no surprise that they are capable of creating quality measuring tools at such a consistent pace. They nearly perfected the micrometer and have maintained that excellence throughout the years. Starrett is a good brand to look into when buying a standard micrometer.

You are very unlikely to come across a Starrett micrometer that doesn’t measure accurately without being subjected to a substantial amount of abuse. Their digital micrometers face some stiff competition that keeps them from being the top dog but their standard analog mics are the best of the best.


Best budget micrometer brand

Anytime Tools

Anytime Tools is new to the game. Started in 1999, they have really come on strong. 20+ years in the industry might sound like a long time but and when it comes to measuring tools many of the players in the game have been around for decades not years.  Starrett and Mitutoyo have each been making gauges for over 100 years.

Much cheaper than other micrometer manufacturers such as Starrett, Mitutoyo or Fowler, Anytime Tools is an American company but I am fairly certain they source their products from another country. The good thing is that it seems to have no effect on their quality. They are consistently producing tools comparable to other big name manufacturers and at a fraction of the price.

As a side note, Anytime Tools also owns iGaging which has also been producing consistent quality measuring instruments.

Best digital micrometer


Mitutoyo is hands down the best digital micrometer manufacturer. Their Digimatic line of digital micrometers blows the competition away. They come at a premium cost, but the price is worth it.  Mitutoyo digital mics are the standard by which all other micrometers should be judged.

The build quality and accuracy of Mitutoyo’s Digimatic micrometers is second to none. They are precise, accurate and hold up very well to all types of abuse they might encounter in a normal machine shop environment.

If you really want the best, consider their QuantuMike. Read our review to understand why.

Best budget digital micrometer brand


Rexbeti is a newer competitor in the digital micrometer space. What they lack in experience they certainly make up for in quality.

While they can’t quite compete with the likes of Mitutoyo and their Digimatic micrometers, they do come pretty darn close at a fraction of the price. For most users, the .0001” accuracy of the Rexbeti digital micrometers will be more than sufficient.

One concern with just about all of the cheaper digital micrometers is that the battery life is much shorter than higher end models. Not a deal breaker but think about keeping some spares on hand so you know the tool is ready to go when you need it.

Also, if you won’t be using the micrometer frequently then think about taking out the battery between uses to save on battery life.

Best used analog micrometer brand


We already covered Starrett’s long track record of producing excellent micrometers above. Just a reminder that this is a very good thing for anyone shopping for a quality used mic as well.

Very little has changed over the years with their standard micrometer line. There have been small variations in the frames and other components but nothing earth shattering. The most important aspect of their micrometers hasn’t changed. The accuracy has consistently been excellent.

While it would be great to purchase a brand-new micrometer and care for it lovingly from day one, sometimes you just want to save a little cash. The good news is that as long as you verify the accuracy of the tool, there is very little reason to expect that a used micrometer would perform any differently than a new one.

In fact, a huge portion of Starrett micrometers made decades ago are still measuring good as new. They aren’t the only ones either just one of the most consistent. For some more used micrometer recommendations see other brands to consider section below.

Best used digital micrometer brand


Digital micrometers are different from your standard analog micrometers. They have changed substantially over the years.

The earliest digital micrometers were not nearly as reliable. If you are looking for a used digital micrometer, stick with something from Mitutoyo’s Digimatic line. They have been exceptional for many years.

There have been other good digital micrometers over the years from various manufacturers, but the quality has been kind of up and down. Some had battery life issues. Others are not nearly as accurate as you would hope. Battery life is easily remedied by keeping a spare in your toolbox. They are cheap enough nowadays.

When it comes to any micrometer, analog or digital, accuracy is the most important factor.

At the risk of sounding like a broken record, check the accuracy of any used tools before purchasing.


Please note there are also an assortment of mechanical digital micrometers on the market. Some people like them. I have never been that person. Their greatest positive is that they don’t require batteries. Unfortunately, all of the mechanical digital micrometers I have used were not precise enough for my taste. They are not something that I recommend but mechanical digital micrometers are an interesting tools nonetheless.

Other brands to consider

fowler micrometer
Fowler micrometer

While we have listed the absolute cream of their crop in their respective categories, there are many other brands to consider.

The hard part is that unfortunately many brands which were known for their quality in years past have moved manufacturing to new locations and quality has suffered as a result.

This can make it difficult to know whether their tools are quality or trash because they simply aren’t consistent.

I recommend the following brands for both new and used tools. Still make sure to verify their accuracy whether buying new or used. You never know how the previous owner or the UPS man treated them.

  • Fowler
  • Brown and Sharpe
  • Etalon

Things to consider when buying a micrometer new or used

Check the specified accuracy

Most micrometers should be accurate to .0001”. Some of the best such as the Mitutoyo digital mics listed above are good to .00005”. That’s twice as good and going to be overkill for most users.

One thing to watch out for is that some older micrometers are only accurate to .001”. If you only need accuracy of .001” then go with a caliper instead. They provide more versatility in your measurements. You should be buying a micrometer for extreme accuracy. Avoid mics that are only accurate to .001”

Check the accuracy yourself

gauge block set
Gauge block set

Micrometers are precision measuring tools. Because their accuracy is so important, it is essential that its accuracy is verified before purchasing if used or immediately after receiving the tool if new.

Take a known standard such as a set of calibrated gauge blocks and check the tool at various steps across its measuring range.

For example, if you have a 0-1” micrometer, try to check it at 0.000”, .250”, .500”, .750” and 1.000”. Sometimes this might not be possible but it is good practice to check at random intervals. Many times, users will only check the tool at the two ends of the measuring ranges, in this case 0.000” and 1.000”. In most cases, this is sufficient but if you can check intervals in between it will be a better verification of the accuracy.

How to care for your micrometer

anytime tools 0-1" micrometer in case
The best type of micrometer case

Look for a micrometer with a case. For used tools, this is a great indicator that the tool was well cared for. A case doesn’t need to be anything fancy.

I have seen used tools with purple velvet lined cases. They were actually the worst. The velvet, felt or whatever the material was gets dirty with oil and coolant eventually. A simple, easy to clean plastic case is the best type to have.

If you keep your micrometer in a case or toolbox, you will be handling 95% of the care needed. You would think that a tool as precise as a micrometer would be a delicate instrument. In reality, they are quite rugged.

Keep your mic clean and out of harms way and it will measure accurately for many years to come.

Do I need a calibration or NIST traceable certificate?

No, a calibration certificate is not needed. You need to verify the accuracy yourself and should make sure to do it regularly.

The best practice is to check the accuracy every time you use the micrometer. You should always assume that the janitor at your shop or your kids in your garage have knocked the tool on the floor and put it back in its place hoping no one will be any wiser.

A calibration certificate only certifies that the tool was accurate somewhere else. It doesn’t do you any good in your shop.

Tips for finding a quality used micrometer

Don’t be afraid to explore Craigslist or Facebook for cheap micrometers. Yard sales and estate sales are another good option for budget tools.

In most cases, people will price them one of two ways. Either same as brand new or dirt cheap.

Do not buy used at like new prices. If it isn’t a quarter or a third of the new price then avoid the deal. You would be better off spending a little more and knowing the history of the tool.

If you can find a good cheap used micrometer there is no reason to believe it won’t last for years to come.

If there are any tips we forgot please let us know and share them in the comments below.

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Mitutoyo QuantuMike Review

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Case is simply standard


Straight to the point. The Mitutoyo QuantuMike digital micrometer is an excellent inspection tool. It does everything an ordinary micrometer does but four times faster. Simply put, this is a top of the line measuring tool but the quality comes at a price.

Let’s get into the features.


The QuantuMike has a big easy to read LCD display. It reads measurements in both inches and millimeters. Inch and metric values are switched at the press of a button.

Speaking of buttons…

The buttons on this micrometer and frankly all of the Mitutoyo Digimatic micrometers I have used, pull off something that seems very simple but in practice isn’t. The buttons are both easy to use and hard to press on accident. What this means is that your measurements are never lost because you accidentally hit the origin button. It can be hard to describe how the feel of a tool plays into its quality. In this case the QuantuMike just feels good.

Build quality

The build of the QuantuMike digital micrometer is excellent. None of the plastic and metal components of the mic seem cheap or flimsy. It’s solid. One potential negative is that some may find the weight of tool a little on the heavy side. I have never found this to be the case but all of Mitutoyo’s Digimatic micrometers are balanced differently than a normal, non-digital micrometer which might feel strange to some. It may take a little getting used to but once it clicks, you won’t want to go back to a standard mic.


Battery life for the QuantuMike is listed at 2.4 years. That seems a little long to me, but in practice the standard SR44 battery lasts long enough that I don’t think about it and just try to keep an extra battery on hand. This has been my experience with what I would call a medium amount of use in your standard machine shop. If you are going to use it in your garage sporadically, then I would venture to guess the battery will die of old age before being drained.

Protection from the elements

The QuantuMike has an IP rating of IP65. IP stands for ingress protection and the two numbers tell you how well protected from solids and liquids the instrument is. Protection from dust and coolant is what you should look for in an IP rating.

The first digit, 6 in this case, is for solids protection and the QuantuMike is completely protected from dust. This is the highest level of solids protection on the IP rating scale.

The second digit, 5 for the QuantuMike, is for liquids protection. The QuantuMike is protected from water jets from any direction. 

The video below shows what level of protection this provides. I would not recommend recreating the test at home with something as nice as this digital mic. Practically, it means your tool will be safe from splashing coolant. However, you should still do your best to keep it clean and dry.

Speaking of clean and dry, the provided plastic case will help you keep it that way. The QuantuMike comes with a fairly standard plastic case but it gets the job done. I should also note that while not all micrometers come with a case, I would certainly expect one for a tool in this price range.


comparing high and low accuracy and precision

Let’s face it, accuracy is by far one of the most important qualities of a micrometer. It’s a measuring tool so it isn’t worth much if it won’t measure with accuracy and precision. Luckily the QuantuMike is extremely accurate. Boasting .00005”/.001mm accuracy, this micrometer is highly accurate and precise. Measurements repeat very well.


The standout speed of the QuantuMike is what sets it apart from other digital micrometers. Each revolution of the thimble moves the anvil in or out .080” or 2mm.

That is four times faster than a standard micrometer. Not the type of feature that matters to a hobbyist even though it is convenient, but for someone checking hundreds or possibly thousands of parts per day it can mean a huge amount of time saved.

Most machinists will use a 6” caliper or a 0-1” micrometer more than any other measurement device. It’s a good idea to have a quality set for these highly used tools.

Other features

  • Carbide tips
  • Thimble ratchet for consistent measurements
  • Measurement lock
  • Some versions have SPC output
  • 1 year warranty, 3 if registered with Mitutoyo


The Mitutoyo QuantuMike digital micrometer is an excellent piece of measuring equipment. The precision and accuracy are top knotch. Battery life is looooooooooong and the speed of measurement is second to none. If you can afford it, you won’t regret it.

What to consider when buying a digital micrometer


The price and the quality affect the overall value of a micrometer. The tricky part is that they really only come in two types, cheap and expensive. There isn’t much middle ground. The hard part is that price does not equal quality. Brands vary wildly in terms of quality. Mitutoyo is one of, if not the best micrometer manufacturer and their quality is in line with their prices. Expensive but worth it to the right user.


Anyone who wants or uses a micrometer needs an accurate measurement. The question is how accurate? Experienced users know the tolerances they need when it comes to a measuring tool. This micrometer measures to 0.00005” or .001mm and that is likely overkill for most people unless they work in a machine shop.

Many might not even know amount of accuracy they need. If this is the case, you would likely be perfectly fine going with a digital caliper. Like micrometers, calipers have a big range of prices. The difference is that calipers are quite a bit cheaper on the average than micrometers.

If you are just getting started when it comes to measurement, think about Mitutoyo calipers if your budget allows or this VINCA caliper. Mitutoyo is pretty consistent with their quality across most of their measuring tools but the VINCA caliper comes pretty close at a much cheaper price.

Absolute or incremental mode

Measurements can be taken in two forms. Absolute values or incremental values. Not all digital micrometers have incremental mode.

Absolute gives you a measurement from a zero point. For a 1-2” micrometer, the zero point would be 1”.

Incremental measures from a specific standard. Using the same 1-2” micrometer in incremental mode would allow the zero to be set at something other than 1”. The display would then read the deviation from the standard you are using such a set of gage blocks.

IP rating

Micrometers are usually rated at one of three IP ratings.

No rating which means there is no protection. Be especially careful around coolant.

IP54 means dust can get into the tool but it won’t affect it and that splashing water is fine. This is usually enough for most use cases.

IP65 is protected from dust and any amount of water that it would normally be exposed to. Anything over this is overkill.

ingress protection (IP) ratings solids description
ingress protection (IP) ratings liquid protection

Data ouput

An SPC output lets you send measurements to a printer or computer. Most won’t need this feature, but it could come in handy in a high volume machine shop.

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Rexbeti 0-1″ Digital Micrometer Review

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Cheap price

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Few extra features


Rexbeti isn’t exactly a household name when it comes to inspection tools such as this 0-1” digital micrometer. What it lacks in name recognition, it makes up for in price but the question is can the quality keep up?
The Rexbeti 0-1” digital micrometer has a .00005” or .001mm resolution which is standard for most digital micrometers. It has an accuracy of +/- .0001” which is only slightly worse than some of the best digital mics such as this one from Mitutoyo but better than most budget options. Prices fluctuate some but the Rexbeti sacrifices very little in accuracy while cutting the cost dramatically.
The digital readout on this set of micrometers is large and easy to read. The display has a simple button layout with only 3 buttons on the face. These primary buttons are on/off, one for switching units between inches and millimeters, and one for zeroing the tool.

The Rexbeti 0-1” digital micrometer features a ratchet stop for taking consistent measurements. The ratchet stop when used correctly allows the user to exert a controlled amount of force when taking readings. This results in more accurate and consistent measurements. Additionally, when not in use this digital mic has an auto shut off feature to save battery life. The tool also comes with an extra battery and a protective case for storage.


Beyond these simple features this Rexbeti micrometer doesn’t have anything too fancy going on. What it lacks in extras though, it makes up for in accuracy. When compared to many other budget digital micrometers, its accuracy stands out for the price. These Rexbeti 0-1” digital micrometers are a great buy at the price and capable of measuring up to all but the most precise digital micrometers.

iGaging 0-1″ Digital Micrometer Review

igaging digital micrometer
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Extra features

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Battery life


iGaging is a popular brand for budget friendly inspection tools. This set of digital micrometers is no different. They have a measuring resolution of .00005” or .001mm and an accuracy of +/- .00015” which equates to +/- .003mm. While not as good as some digital micrometers which cost 2-3 times as much, the iGaging digital mics come close at a fraction of the price.
ball attachment for igaging digital micrometer
These iGaging digital micrometers have a very impressive feature set. Some of the extras that aren’t normally seen in its price range are a SPC output and a ball attachment for the anvil. The SPC output allows you to record measurements directly to your computer while the ball attachment allows you to measure round surfaces such as the wall thickness of tubing. Some of the more standard type features include an extra battery and a protective case to keep your tool safe. Carbide tips are a nice bonus that isn’t always seen on budget level digital micrometers. They provide superior wear resistance when compared to normal hardened steel.
A decent size display and simple button layout adorn the face of the tool. With the press of a button the micrometer switches units from inches to millimeters. The ability to switch between absolute and incremental measuring modes is available too. Nothing too out of the ordinary present in the normal use of the mic.
Like most other digital micrometers, this one from iGaging has a little more weight to it than a standard micrometer. Some don’t like the added weight because they feel it makes it harder to maneuver around their workpiece. With a little time and use, I don’t believe the weight will bother anyone.
Now onto some of the negatives. The biggest problem is that some buyers report instances of the display flickering. All of the budget digital micrometers have quality issues such as this one, the bigger problem is that the manufacturer isn’t the most responsive to problems. Another common issue for lower priced tools is limited battery life. For most this shouldn’t be too much of a bother but it’s best to keep an extra battery or two on hand. Lastly, the thimble feels cheap because of the plastic material used.
igaging digital micrometer in case


The simplicity of the display and button layout are a nice touch and will be appreciated by those not as familiar with digital micrometers. The addition of the SPC output and ball attachment put these mics a step above most other entry level digital micrometers. To get a better micrometer you will need to pay 3 times the cost of these mics or more. The iGaging 0-1” digital micrometer is a solid budget priced inspection tool.