3 Ways To Use And Read An Outside Micrometer - WikiHow

Home » How To Read A Micrometer » 3 Ways To Use And Read An Outside Micrometer - WikiHow

Maybe your like

Skip to ContentQuizzes
  • Home
  • Random
  • Browse Articles
  • Quizzes & Games
  • All QuizzesHot
  • Love Quizzes
  • Personality Quizzes
  • Fun Games
  • Dating Simulator
  • Learn Something New
  • Forums
  • Courses
  • Happiness Hub
  • Explore More
  • Support wikiHow
  • About wikiHow
  • Log in / Sign up
Terms of Use wikiHow is where trusted research and expert knowledge come together. Learn why people trust wikiHow How to Use and Read an Outside Micrometer PDF download Download Article Reviewed by Anne Schmidt

Last Updated: February 24, 2025 Fact Checked

PDF download Download Article
  • Measuring with the Micrometer
    • |
  • Reading an Inch Micrometer
    • |
  • Reading a Metric Micrometer
    • |
  • Video
    • |
  • Q&A
    • |
  • Tips
    • |
  • Warnings
    • |
  • Things You'll Need
|Show more |Show less X

This article was reviewed by Anne Schmidt. Anne Schmidt is a Chemistry Instructor in Wisconsin. Anne has been teaching high school chemistry for over 20 years and is passionate about providing accessible and educational chemistry content. She has over 9,000 subscribers to her educational chemistry YouTube channel. She has presented at the American Association of Chemistry Teachers (AATC) and was an Adjunct General Chemistry Instructor at Northeast Wisconsin Technical College. Anne was published in the Journal of Chemical Education as a Co-Author, has an article in ChemEdX, and has presented twice and was published with the AACT. Anne has a BS in Chemistry from the University of Wisconsin, Oshkosh, and an MA in Secondary Education and Teaching from Viterbo University. This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources. This article has been viewed 770,319 times.

If you are a machinist, manufacturing, or engine professional, exact measurements are an everyday must. When it comes to measuring cylindrical or spherical objects, an outside micrometer would be the best tool to use. A well calibrated micrometer can be difficult to use, but with patience and practice, this tool can be a part of your skill set.

Steps

Method 1 Method 1 of 3:

Measuring with the Micrometer

PDF download Download Article
  1. Step 1 Familiarize yourself with the anatomy of a micrometer. 1 Familiarize yourself with the anatomy of a micrometer. Some parts are stationary while others are movable.[1]
    • Ratchet stop
    • Thimble
    • Frame
    • Thimble lock
    • Spindle
    • Anvil
    • Sleeve
  2. Step 2 Clean the anvil and spindle before beginning. 2 Clean the anvil and spindle before beginning. Use either a clean sheet of paper or soft cloth, and hold it between the anvil and the spindle. Gently twist and close on the sheet or cloth. Slowly, pull out the sheet or the cloth.
    • This practice isn't a necessary step for measuring, but keeping the surfaces of the anvil and spindle clean ensures precise measurements.
    Advertisement
  3. Step 3 Hold the object in your left hand and place it against the anvil. 3 Hold the object in your left hand and place it against the anvil. The anvil is stationary and can withstand more pressure than the spindle. Make sure the object doesn't move or scratch the surface of the anvil.
  4. Step 4 Hold the micrometer with your right hand. 4 Hold the micrometer with your right hand. The frame will rest gently on your palm.
    • You can also fasten the frame on a stationary vise; this helps free up both hands for the measuring process.
  5. Step 5 Spin the ratchet counter clockwise. 5 Spin the ratchet counter clockwise. Be sure the 0 on the thimble is lined up with the scale on the sleeve.
  6. Step 6 Twist until the spindle is against the object. 6 Twist until the spindle is against the object. Apply enough force. The thimble often clicks. Three clicks is a good stopping point.
  7. Step 7 Set the thimble lock while the micrometer is still on the object. 7 Set the thimble lock while the micrometer is still on the object. Even though it is on lock, the spindle can still be moved.[2]
  8. Step 8 Slide out the object carefully. 8 Slide out the object carefully. Be sure to avoid scratching either surfaces of the anvil or spindle; the slightest scratch can ruin the micrometers measuring accuracy.
  9. Step 9 Write down the measurements before unlocking the spindle. 9 Write down the measurements before unlocking the spindle. If the spindle loosens, be sure to remeasure.
    10. Advertisement
Method 2 Method 2 of 3:

Reading an Inch Micrometer

PDF download Download Article
  1. Step 1 Learn the different number scales on the thimbles. 1 Learn the different number scales on the thimbles.
    • On the sleeve is a scale that measures by the one-hundred thousands or 1/10 of an inch; in decimal form it would be .100.
    • In between those whole numbers are three lines that represent twenty-five thousandths of an inch; in decimal form, it would look like .025.
    • The thimble has evenly spaced lines that represent one-thousandth of an inch; in decimal form it would be .001.
    • Above the whole number scale on the sleeve are lines that measure to ten-thousandths of an inch; in decimal form it looks like .0001.
  2. Step 2 Read the whole number on the sleeve first. 2 Read the whole number on the sleeve first. The last visible number will read as the thousandths. For example, if the last number you can see on the sleeve is 5, then it would read 500 thousandths, or .00005.
  3. Step 3 Read how many lines come after the whole number. 3 Read how many lines come after the whole number. Look at the individual markings exposed next to the 100 thousandths and multiply each marking by .25.. In this case 1 x .025 would be .025.
  4. Step 4 Find the number and corresponding marking on the thimble scale closest to but underneath the measurement line on the stock. 4 Find the number and corresponding marking on the thimble scale closest to but underneath the measurement line on the stock. If it's closest to 1, then it would be .001.
  5. Step 5 Add those three numbers together. 5 Add those three numbers together. In this case it would be .500 + .025 + .001 = .526.
  6. Step 6 Flip the micrometer over to read to the 10 thousandths marking. 6 Flip the micrometer over to read to the 10 thousandths marking. Read that line that lines closest with the sleeve. If, for example, it lines with 1, then the measurement will read .5261
    7. Advertisement
Method 3 Method 3 of 3:

Reading a Metric Micrometer

PDF download Download Article
  1. Step 1 Learn the different number scales on the thimbles. 1 Learn the different number scales on the thimbles.
    • The line on the sleeve usually has top line showing millimeters, and below that line the marks represent half millimeters.
    • The marks on the thimble usually go to 50, and each line represents a hundredth of a millimeter or .01 mm.
    • The horizontal lines above the scale on the sleeve will measure to the thousandth of a millimeter, or .001 mm.
  2. Step 2 Read the number of millimeters first. 2 Read the number of millimeters first. If the last line you saw were a 5, then you would have 5 mm thus far.[3]
  3. Step 3 Incorporate all the half millimeters in your measurement. 3 Incorporate all the half millimeters in your measurement. If you have one mark that would be .5 mm.
    • Don't count a mark that is barely showing; the reading on the thimble might be getting close to 50.
  4. Step 4 Find the number of .01 millimeters. 4 Find the number of .01 millimeters. If the line on the thimble reads 33, then you'd have .33 mm.
  5. Step 5 Add up all three lines. 5 Add up all three lines. In this example, add 5 + .5 + .33. The measurement is 5.83 mm.[4]
  6. Step 6 Add the thousandths. 6 Add the thousandths. If the thousandths read a 6, then at .006 to the measurement. In this example, it would be 5.836
    • The main time you should incorporate the thousandths measurement is if the object has less tolerance for the pressure applied by the micrometer.
    7. Advertisement

Community Q&A

Search Add New Question
  • Question How do you measure a bearing's half-thickness? Community Answer Community Answer Use a ball bearing on the inside then subtract the ball bearing diameter from the overall dimension of the ball bearing and the plain bearing shell. Thanks! We're glad this was helpful. Thank you for your feedback. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow Yes No Not Helpful 0 Helpful 14
  • Question What are micrometers used for in mechanics? Community Answer Community Answer The most common use I can think of would be measuring piston diameter and inside of cylinder bore to check wear. There are probably many other uses, thickness of shims, wear of transmission parts, thickness of break rotors, etc. Thanks! We're glad this was helpful. Thank you for your feedback. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow Yes No Not Helpful 5 Helpful 6
  • Question How do I clean an inside micrometer? Gerald Phillip Harvey Gerald Phillip Harvey Community Answer A piece of paper or a soft cloth close the spindle, gently pulling the paper or cloth out. Thanks! We're glad this was helpful. Thank you for your feedback. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow Yes No Not Helpful 0 Helpful 3
Ask a Question 200 characters left Include your email address to get a message when this question is answered. Submit Advertisement

Video

Tips

  • Remember also that an outside micrometer, when used correctly, is much more accurate than calipers. Thanks Helpful 50 Not Helpful 21
  • Practice -- you will develop a "touch" or "feel" for it. Thanks Helpful 38 Not Helpful 20
  • Measure the desired object multiple times as a check on your work. Thanks Helpful 32 Not Helpful 18
Show More Tips Submit a Tip All tip submissions are carefully reviewed before being published Name Please provide your name and last initial Submit Thanks for submitting a tip for review! Advertisement

Warnings

  • It is assumed when a micrometer is used, that an accurate and precise measurement is desired. Ensure your micrometer is properly calibrated. They do lose accuracy with use, and must be adjusted every 36 months according to NIST. Check more often when frequently used. Thanks Helpful 21 Not Helpful 12
Advertisement

Things You'll Need

  • Micrometer
  • Micrometer tools:
    • Standard – The standard is an item of precisely calibrated length and flatness which is used to verify the accuracy of the micrometer or to reset it if it is found to be inaccurate. Standards are typically a round or rectangular piece of steel. They are employed just prior to using a micrometer or may be used on a set schedule as part of a calibration program.
    • Wrench – insert in hole on back of the stock to adjust the micrometer if needed.

You Might Also Like

Read a Dial IndicatorHow toRead a Dial Indicator Use a Vernier CaliperHow to Read a Vernier Caliper for Super Precise Measurements Use and Read Dial Vernier CaliperHow toUse and Read Dial Vernier Caliper Read a CaliperHow toRead a Caliper Use CalipersHow toUse Calipers Use a RulerHow to Use a Ruler: Standard & Metric Read a Measuring TapeHow to Read a Tape Measure in Inches or Centimeters Measure Thickness of PaperHow toMeasure Thickness of Paper Measure in InchesHow Big Is an Inch? Here's How to Measure Accurately Read a RulerHow toRead a Ruler Read a Torque WrenchHow toRead a Torque Wrench Measure MillimetersHow to Use a Ruler to Measure in Millimeters (Plus Estimating Lengths) Measure Cylinder BoreHow toMeasure Cylinder Bore Read a Measuring Tape in MetersHow to Read a Measuring Tape in Meters (Even if You Hate Math) Advertisement

References

  1. ↑ https://www.me.psu.edu/cimbala/me345/Lectures/Labs/Basic_statistics/How_to_read_micrometer.pdf
  2. ↑ https://www.me.psu.edu/cimbala/me345/Lectures/Labs/Basic_statistics/How_to_read_micrometer.pdf
  3. ↑ https://www2.mitutoyo.co.jp/eng/useful/E11003/pdf/10.pdf
  4. ↑ https://www2.mitutoyo.co.jp/eng/useful/E11003/pdf/10.pdf

About This Article

Anne Schmidt Reviewed by: Anne Schmidt Chemistry Instructor This article was reviewed by Anne Schmidt. Anne Schmidt is a Chemistry Instructor in Wisconsin. Anne has been teaching high school chemistry for over 20 years and is passionate about providing accessible and educational chemistry content. She has over 9,000 subscribers to her educational chemistry YouTube channel. She has presented at the American Association of Chemistry Teachers (AATC) and was an Adjunct General Chemistry Instructor at Northeast Wisconsin Technical College. Anne was published in the Journal of Chemical Education as a Co-Author, has an article in ChemEdX, and has presented twice and was published with the AACT. Anne has a BS in Chemistry from the University of Wisconsin, Oshkosh, and an MA in Secondary Education and Teaching from Viterbo University. This article has been viewed 770,319 times. 293 votes - 71% Co-authors: 36 Updated: February 24, 2025 Views: 770,319 Categories: Featured Articles | Car Maintenance and Repair In other languages Spanish Portuguese Russian Italian Japanese
  • Print
  • Send fan mail to authors
Thanks to all authors for creating a page that has been read 770,319 times.

Reader Success Stories

  • Anonymous

    Anonymous

    Oct 19, 2018

    "This is very helpful. I read the article some time ago before my technical test, which will allow me to seat for my..." more
More reader stories Hide reader stories Share your story

Did this article help you?

Yes No Advertisement Cookies make wikiHow better. By continuing to use our site, you agree to our cookie policy. Anne Schmidt Reviewed by: Anne Schmidt Chemistry Instructor 293 votes - 71% Click a star to vote Co-authors: 36 Updated: February 24, 2025 Views: 770,319 Anonymous

Anonymous

Oct 19, 2018

"This is very helpful. I read the article some time ago before my technical test, which will allow me to seat for my..." more Sayantani Chatterjee

Sayantani Chatterjee

Aug 25, 2017

"I am a science student and we get to practice only once in our labs, so this article was helpful in remembering..." more Rated this article: Devansh Srivastava

Devansh Srivastava

Jul 3, 2017

"This helped me a lot in my studies. It also helped me in the completion of my project. " Rated this article: Anonymous

Anonymous

Jun 22, 2016

"Helpful with reading scale on a metric micrometer." Anonymous

Anonymous

Feb 14, 2024

"This helped me pass my micrometer test." Share yours! More success stories Hide success stories

Quizzes & Games

Am I Smart QuizAm I Smart QuizTake QuizMusic Notes & Symbols TestMusic Notes & Symbols TestTake QuizDo I Have Common Sense QuizDo I Have Common Sense QuizTake QuizCognitive TestCognitive TestTake QuizWhat Age Is My Brain QuizWhat Age Is My Brain QuizTake QuizIQ TestIQ TestTake Quiz

You Might Also Like

Read a Dial IndicatorHow toRead a Dial IndicatorUse a Vernier CaliperHow to Read a Vernier Caliper for Super Precise MeasurementsUse and Read Dial Vernier CaliperHow toUse and Read Dial Vernier CaliperRead a CaliperHow toRead a Caliper

Featured Articles

15 Signs Your Ex Misses You (and What to Do About It)15 Signs Your Ex Misses You (and What to Do About It) Observe Hanukkah (From Candle Lighting to Latke Frying)How to Observe Hanukkah (From Candle Lighting to Latke Frying)165+ "You Are Special" Quotes For Friends, Family, Partners & More165+ "You Are Special" Quotes For Friends, Family, Partners & More115+ Brain Teasers For Adults & Kids (With Answers!)115+ Brain Teasers For Adults & Kids (With Answers!)When Will I Get My First Kiss QuizWhen Will I Get My First Kiss Quiz17 Believable Excuses to Miss Class At the Last Minute17 Believable Excuses to Miss Class At the Last Minute

Trending Articles

Let Us Rate You 1-10: Attractiveness Scale QuizLet Us Rate You 1-10: Attractiveness Scale QuizHow Much Do I Mog QuizHow Much Do I Mog QuizAm I Annoying QuizAm I Annoying QuizCollege Grad Intelligence Test: Can You Score An A+?College Grad Intelligence Test: Can You Score An A+?How Nonchalant Am I QuizHow Nonchalant Am I QuizHow Weird Am I QuizHow Weird Am I Quiz

Featured Articles

Speed Up Your Slow-Performing Mobile DataHow to Speed Up Your Slow-Performing Mobile Data Get a Nice BodyHow to Get a Nice BodyIce Cream Personality TestIce Cream Personality TestDress for WinterHow toDress for WinterNicknames for Your Girlfriend: 125+ Funny, Sweet & Clever IdeasNicknames for Your Girlfriend: 125+ Funny, Sweet & Clever Ideas Give Someone a Great GiftHow to Give Someone a Great Gift

Featured Articles

What Would My Life At Camp Half-Blood Be Like QuizWhat Would My Life At Camp Half-Blood Be Like QuizThe Best Hairstyles for Guys with Big ForeheadsThe Best Hairstyles for Guys with Big Foreheads22 Best Ideas for Scary (and Funny) Pranks22 Best Ideas for Scary (and Funny) Pranks Text Yourself: Fake Text Messages, Reminders, and MoreHow to Text Yourself: Fake Text Messages, Reminders, and MoreAccurate Omegaverse Quiz: 100% GuaranteeAccurate Omegaverse Quiz: 100% GuaranteeThe Hardest & Most Difficult Riddles for AdultsThe Hardest & Most Difficult Riddles for Adults

Watch Articles

Marinate Chicken: 4 Recipes and a Step-By-Step GuideHow to Marinate Chicken: 4 Recipes and a Step-By-Step GuideClean Shower TileHow toClean Shower TileDo Oblique CrunchesHow toDo Oblique CrunchesSimple Ways to Riffle Shuffle and Bridge Playing CardsSimple Ways to Riffle Shuffle and Bridge Playing CardsMake Black CoffeeHow toMake Black CoffeePlant a Seed in a PotHow toPlant a Seed in a Pot

Trending Articles

Can We Guess How Tall You Are QuizCan We Guess How Tall You Are QuizHow Would My Fandom See Me If I Were a Fictional Character QuizHow Would My Fandom See Me If I Were a Fictional Character QuizGet Claimed by Your Godly Parent (Percy Jackson Quiz)Get Claimed by Your Godly Parent (Percy Jackson Quiz)Am I a Furry QuizAm I a Furry Quiz170+ Deep, Heartfelt & Passionate Love Messages to Send Your Guy170+ Deep, Heartfelt & Passionate Love Messages to Send Your GuyThe World's Hardest Riddles (for Kids & Adults)The World's Hardest Riddles (for Kids & Adults)

Quizzes & Games

Memory TestMemory TestTake QuizDo You Have What It Takes To Become A Millionaire?Do You Have What It Takes To Become A Millionaire?Take QuizIQ Test For KidsIQ Test For KidsTake QuizFinish the Phrase QuizFinish the Phrase QuizTake QuizQuick IQ TestQuick IQ TestTake QuizAm I Smarter than a 5th Grader QuizAm I Smarter than a 5th Grader QuizTake Quiz wikiHow
  • Categories
  • Cars & Other Vehicles
  • Cars
  • Car Maintenance and Repair
wikiHow Newsletter You're all set! Helpful how-tos delivered toyour inbox every week! Sign me up! By signing up you are agreeing to receive emails according to our privacy policy.
  • Home
  • About wikiHow
  • Experts
  • Jobs
  • Contact Us
  • Site Map
  • Terms of Use
  • Privacy Policy
  • Do Not Sell or Share My Info
  • Not Selling Info
  • Contribute

Follow Us

×

wikiHow Tech Help Pro:

Level up your tech skills and stay ahead of the curve

Let's go! X --759

Tag » How To Read A Micrometer