How to Check and Adjust the Calibration of an Outside and Depth Micrometer

[@johnw.peterson4311]

Keith, you are a good man and an outstanding Machinist. Thank you for your vintage work and edifying videos.

[@chesterdroors1605]

Keith, I've been a Metrologist (calibration technician) for 35 years. I've been watching your videos for years. Every video you make about precision measurements has been spot on. I've even learned a thing or two from you about measuring over the years. Dave in TX

[@brianwilliams8361]

Keith, i do hope your health issues clear up soon, im not a machinist but enjoy your videos very much , and appreciate your honesty when you rarely do screw up , you'd be surprised how many aren't, .

[@PhilG999]

Interesting! I *kinda* taught myself some of this when I was in HS. I had access to the Science Department storage area (one of the few students that did). One day I found a 0-25mm micrometer in a drawer that was seized tight! Seems somebody had closed it entirely (even then I knew that was a no-no) in the Wintertime and this was nearing Summer. Asked the teacher if I could have it. So I took it home and clamped it in a vice and *carefully* opened it up. Took it all apart. Got it zeroed, but didn't calibrate it further. Took it back and showed it to him and he said: "Keep it". I still have it...

[@PixelSchnitzel]

Best I can tell, the hardness tester you sold me is absolutely dead-nuts on. Thanks!!! I do enjoy videos like these even if I'm already familiar; it's great reinforcement and I know others find valuable training info in them.

[@unwired1281]

Retired electrician but have always been fascinated by your trade. One of my favorite places to do service work was a medical R&D facility. I spent way too much time watching and asking questions couldn’t believe the time that went into making and testing the molds for the plastic part they were developing.

[@jonlong4866]

Great information! Thank you Keith for showing us that process. Hope you continue to heal well.

[@rexmyers991]

Excellent lesson! I needed this basic information. Thank you, sir.

[@jjbode1]

Useful addition to your archive. Thanks!

[@CraigLYoung]

I know many will thing this is boring but for someone who use to calibration. It's a very important part of industry.

[@jackpledger8118]

Great video Keith...now I know how to calibrate my depth micrometers.

[@glennstasse5698]

I always wondered what that little spinner wrench was for! Thanks for the info, Kieth.

[@kentuckytrapper780]

Great video Keith, keep'um coming..

[@mdouglaswray]

LOVE to see your videos. Always educational and archival! Thank you!

[@bulletproofpepper2]

Looking good Keith! Thanks for sharing. Thanks for the hot / cold tips.

[@paulputnam2305]

Great informative video. Thanks

[@Metaldetectiontubeworldwide]

You can read my video demand, it seems ..lol I Just started my job as calibration engineer 🤩. And still in my training so this is pure G☆O☆L☆D☆

[@gagasmancave8859]

I have a selection of both metric and imperial mic's also bit new and old. Now you have shown me how I should be calibrating my metrology collection, my OCD has kicked in i feel an afternoon of calibrating coming onwith a calibration register together produced

[@craxd1]

I took it for granted that everyone knows how to calibrate their mics, as I've never seen many videos about it, to be honest. We had a joke, when I worked at a large pump part manufacturer, about a machinist grinding down the company's standards/gauge blocks to fit his mic, which he thought was correct, and the blocks, not.

[@donkinzer5718]

You mentioned, when discussing calibration of the outside micrometer, the importance of ensuring that the anvils are clean. The same consideration applies to the depth micrometer when changing rods - you want to be sure that the mating surfaces are clean.

[@billmorris2613]

Good morning to all from SE Louisiana 10 Jun 22.

[@elsdp-4560]

Thank you for sharing. Enjoyed.

[@wallysprint]

Thanks for the lesson Sir!

[@magnusklahr8190]

An actual callibration is made by using gage blocks of different sices to check the entire lengt of the screw. A good cero does not tell you What it will read on for example 1/2” or 12,7mm. You also check the paralellity between the anvil and the screw.

[@frankward709]

Thanks for the video

[@jacquespoirier9071]

Very good video One fact that becomes very important when we talk in tenth of a thou, it is the temperature of the part versus the temperature of the instrument. What I do is that I store the instrument with the part to be ,measured for a few hours before taking my measurement and I wear thin gloves to avoid warming the instrument with my hands. Calibration is one thing, the way you use it is another and for sure the combination of both gives the credible result, I say credible because when i speak in terms of tehts of a thou, there is so many variables linked to the human factor that for the same part with the same measuring instrument, the result can differ significantly.

[@billmorris2613]

Thanks for showing us how to calibrate the tools. Luckily I have never needed to adjust the calibration on my mics. I use them mainly when rebuilding auto and aircraft engines.

[@tpobrienjr]

Keith, how about angular measurements? Do you have a good way to calibrate angle-measuring instruments? Thanks for the demo - will be mandatory watching for grandson Chris.

[@MatthewScott]

Morning Keith

[@kimber1958]

THANKS KEITH

[@grntitan1]

One common mistake people make with mics, is too much thimble pressure when measuring items. Worked with a guy who would crank down until he got the reading he wanted. Not all micrometers have a ratcheting thimble. I do much prefer a mics with the ratcheting thimble. Gives a good repeatable reading.

[@ellieprice363]

I can identify with this problem checking mikes. I use a very light “slipping” feel with my thumb and index on the barrel when checking calibration on mikes that don’t have a ratchet. It’s also very easy to use too much pressure when checking depth mikes. 40 threads per inch is a very powerful lifting force so you have to be careful. I’m glad that Keith addressed this subject.

[@grntitan1]

@@ellieprice363 Very much so on the depth mics. I use a Mitutoyo with analog readout. It has a ratcheting thimble. Really helps to keep from it jacking itself up and giving a false reading.

[@robertlark7751]

Don't care for ratchets as they can not be "caliibrated". Yes, they will repeat, but that doesn't mean the reading is accurate. Prefer to use my "feel" which I have spent years developing.

[@ellieprice363]

@@robertlark7751 I have to agree I use the finger slip method even on mikes that have a ratchet.

[@johngermain3535]

reminds me of my working days doing 600 tools a year checking to calibrated standards

[@RRINTHESHOP]

Nice demo Keith. Thanks for sharing.

[@delstone1919]

Great video on basic calibration but what about anvils which are worn concaved, convexed or even grooved?

[@tacticalrabbit308]

I'm not a machinist but picked up a gage block to check my dial calipers with

[@WilliamTMusil]

Hiya Keith

[@patmchugh1327]

What your showing is just good practice always zero your equipment before using. Calibration will check the micrometer thimble throughout its range check flatness and parallelism of working faces. If you have a set of good gauge blocks and a lever DTI gauge you can easily do a full calibration of micrometers and depth micrometers

[@haroldsprenkle4173]

If you have a ball bearing ball, you can check out flatness of anvil to thimble? Have an old set of starrett Mike's that had been dropped or something, put them in vice, did a twist, tappety tap with a 4 oz hammer, little bit of lapping, good as new. Ok, I will put them up against any new import mikes. Grab an odd sized block and check other than .025 increment. Just have to check. I usually check my depth mike out with my 123 block. Quality of cheap 123 blocks is great, down to the tenths, throw your Mike's on the first. I am using an old set of Tumiko depth Mike's, adjusters have red on them, all rods seem spot on, wonderful old set, no tenths vernier, but as close to zero as my old eyes can see. Tumiko or tubular micrometer, or Sheire? Tumiko stuff is good stuff, don't pass it by. Don't ignore the lufkin and union tool tools either. But right now guage block sets are cheap, pick up a set.

[@haroldsprenkle4173]

Hey another comment, helps your algorithm, back when, working in tool room of a furniture factory, ruined many a set of calipers, guys wanted the depth rod to go into an .093 hole 2 inches, we had a grinder with a 2 inch wheel. This was when digital calipers were becoming common, they were great in that with a push of a button, inch or metric. Most digitals checked against my 1.000 starrett standard measured between .999 and 1.001, mitutoyos usually read 1.0000, plant provided verniers always read 1.000. I used to go to great lengths setting my calipers, I am partial to Brown and Sharpe, stoning with translucent Arkansas hone, see no light, set zero. Anymore I set with a standard. Ok my eyes a aren't as good anymore. When the 20 dollar Bill's came out with the microprinting I could read it, can't anymore. Used to be able to read a scale to .005, now I have to clean my reading glasses to see the lines. Ok, I have commented for your algorithm, love your web site, keep looking on it for metric chart for my Hendey, I have 14 positions on my tumbler, most charts show 12. Not on the top of my list, but I am going to teach my Hendey how to cut metric threads, just have to cut a 127, 120, and 100 tooth gears. Have the cutters, got the blank cut out for the 127 hole dividing head plate, should I take it to work and drill it on the HASS or do it with my rotab. Should ask HAAS operator what his reverse comp numbers are first. Ha. Better keep my mouth shut, going to be on other side of wall calibrating cnc. Leveled surface plate and calibrated shops levels plus mine a week ago, getting old, my legs still hurt from all the up and down. Ok, I have commented enough, hope it helps and someone benefits from my verbose comments.

[@crossbowhunter9118]

Which is more accurate a gage block or a standard?

[@EVguru]

I threw out a severa micrometers a few years ago. Every single one would zero fine and correctly read a calibration standard, but they were all junk. They'd come from a production environment and had been used to check the same dimension for many years. Near that dimension some were up to half a thou out. They'd probably been calibrated against a gauge block that matched the nominal dimension they needed to measure. I reset the zero, but was suspicious of why it had been so far off and checked them at multiple dimensions. DON'T ASSUME!

[@alfredpalmiter4398]

Keith, I have a J. T. Slocomb 0 to 1" micrometer. It is a basic model (no tightening ratchet ) It reads about 4 tenths small, on the zero side, and dead on at 1" ( L.S. Starrett 1" standard ) The threads look good, and are clean. How could one end be off, and the other dead on ? Thank you, Al

[@sbrunner69]

Cool!

[@carlwhite8225]

Keith, all of my mics came from my uncles shop and although I got the boxes I got no Spanners. any idea where to get a universal set for Starrett, Brown & sharp and Lufkin ? Great helpful tips and as usual, thanks.

[@Ddabig40mac]

I have seen many of the spanners in the machinist "junk drawer" lots on ebay. Kind of a crap shoot for what they'll fit.

[@Grandpa82547]

I set my mics 30 years ago and haven't done them since. If zero is off by .001, its easier to just add or subtract, than to recalibrate every time I use them. (I only use them a few times a year.)

[@keithgutshall9559]

Mitutoyo has a video to check micrometer they use gage blocks to check the middle of a micrometer in the middle.They use a gage blocks 0.210, 0.420 ,0.605, 0.815 ,And a 1.000.

[@Ddabig40mac]

I'd be interested in seeing the calibration of an inside micrometer, unless the general consensus is use it as a fiddly transfer gauge to an outside mic instead of a direct reading instrument.

[@eliasloozen7948]

Standard lab temperature in Europe (metric standard) is 20°C or 68 °F

[@Captain_Hapton]

"I've never seen a micrometer off more than a thou..." gee, that must be nice.

[@steamrailwilly]

I have a micrometer that does NOT have a hole to adjust the barrel with a spanner wrench. How do I recalibrate that type of micrometer?

[@curtisvonepp4335]

Hey you AOLWAYS CHECK ON BOTH ENDS 😉.

[@TgWags69]

Don't forget the heat from your hands will warm up the mic and affect it. Especially if you get to the point that you are chasing your tail back and forth trying to get it right, you may not realize you've been holding it for ten minutes and now it's 80 or 90 degrees.

[@roadshowautosports]

I wish you had some depth micrometer to adjust actually instead of all dead ons. Just saying that it can be adjusted doesn’t really show how. The depth micrometer doesn’t have the adjust hole and you can’t turn the barrel so, it must be a different way that I don’t know how. I just finished adjusting one and it was hours because the only way I knew was to take off the rod, loosen the nuts, retighten them, try it, and try it, and try it, until I matched the zero. Very time consuming. Thank you anyway for trying to pass the information.

[@brucepeebles4939]

This video would have been more complete if you said a few words about 'care and feeding' of uCrometers. (Such as "do not store with anvils touching lest temp. changes create stress/bending forces")

[@BedsitBob]

68f is 20c.

[@mechelectro2711]

Keith you have demonstrated Zeroing a micrometer, this is not calibrating by a long shot

[@markschwartz830]

Don't keep your standards in the hot/cold garage

[@georgebush8038]

who uses inches?

[@chesterdroors1605]

Americans.

[@Ddabig40mac]

Everyone who can!

[@BedsitBob]

Strictly speaking, you can't calibrate a micrometer. You can only *zero* it.

[@W4BIN]

Every time I turn on my (Chinese) micrometer I have to calibrate it, as in Zero it. Ron W4BIN

[@iteerrex8166]

Just to remind again, be mindful of temperature and touching things. They human body is some 30f hotter then the standard.

[@dennisbrooks4742]

Sound is absolute crap.