Tool Tuesday Ep. 4: Starrett-Webber Gage Blocks

We have a new set of Starrett gage blocks for our granite surface plate. This was my first set of brand new gage blocks and I wanted to share the excitement of opening up these very precise and accurate tools. This set is a Grade B, perfect for inspections and shop use. I give an example of how you can use a stack of gage blocks for comparative measurements.
#abom79 #starrett #gageblocks
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[@jcsrst]

Gauge blocks are fascinating to me. The ability to check all your measuring devices and do absolutely precise measuring is the pinnacle of machinist perfection. Our world would look much different without them!!

[@ericsandberg3167]

Metrology is such an interesting science/profession, I always enjoyed working in the Met lab and learned so much during those sessions. Seeing how all our equipment was traced back directly to NIST was a real education.

[@NutjobGTO]

It's always fascinating how, in a shop full of incredibly large, powerful and complicated machines, some of the most important tools are just inert rectangular blocks. Extremely high precision blocks, but still. Six faces, square corners, zero moving parts, zero surface details, but the huge machine covered in wheels and levers and able to chew through an inch of steel at a pass is dead in the water without them.

[@shubus]

One thing is certain in life: The accuracy of Starrett tools.

[@phuzzygreene]

This was fun. I have really developed an appreciation for metrology (a.k.a. chasing zeros). Thank your for sharing as I enjoy your enthusiasm for your particular art form.

[@patrickboudreau3846]

I think what i love the most about this chanel is the love Abom has for his trade. Not a lot of people are lucky.enough to experience that type of love, not even the very rich. Love the man, love the trade, love the show. Thanks Abom.

[@jasonhull5712]

I just want to say, I’m so grateful and humbled to see the Starrett company is still thriving. In such a throw away society it really does speak volumes to the quality and craftsmanship that name Carry’s. Even if the majority of us can’t afford to own them. We can still appreciate them for the historical footprint they have and continue to leave in this industry. Rock on Starrett ! And if you need any help field testing any of fine quality tools I’d be happy to oblige. 😊

[@utidjian]

Well that quality costs money. For example a Starrett (or Mitutoyo) 6" digital caliper used to cost about US$150 for the base model. Harbor Freight sells one for US$15.

[@jtg2737]

Hello from San Antonio, TEXAS!

[@RobertGracie]

Ah exactly what I need after a long 8 hour shift of work today! an Abom video to sooth the nerves :D

[@alainmare8081]

I believe it is recommended to use gloves to manipulate such high precision gauges. Bare hands can oxidize métal even if you cannot see or feel it. We are talking here about a fraction of 1/10000 inch.

[@chloehennessey6813]

When you have your own set of gauge blocks, huge lathes, tooling worth our whole shop; you are the pinnacle of machinists that we home gamers measure ourselves by.

[@phoolb7326]

Your excitement is Not taken as a Brag or Boast! Presently, I only have a small Sherline lathes and mill but yet own variety of Starrett & Mitutoyo tools. (micrometers, indicators, gauge blocks, pins, and surface plates... The joy of hitting hitting a dimension right on independent of the machine you used is what make this hobby (for me that is) so enjoyable. Just waiting for when I retire and get a larger shop to purchase a bigger lathe and mill. When taken care of nice tools will last forever and provide a lifetime of excitement and happiness as I still have some of my fathers wood tools in my shop which bring back memories every time I use them.

[@SolidRockMachineShopInc]

Nice job Adam. One thing to keep in mind is it takes very heat from touching metal parts to change the size by a few .0001". I bet that the Gage blocks expand by a tenth just by the amount of time you were touching them making it look like the 123 blocks were off a .0001. Just for fun take your 4" block and set your indicator to zero on it without touching it much. Then grab hold of it and within a few seconds you will see the Gage block grow by .0005" to and.001". Tell Lance he did a nice job on the 123 blocks. Steve

[@jasonp9284]

@@SteveColluns-hm2xx Oh snap 😮

[@richardlincoln8438]

​@@SteveColluns-hm2xx It seems that You have made it your life's goal to be butt-hurt about the content on this channel. Why wouldn't You just move along to something that doesn't disgust You as much ?

[@Shrub4Treez]

Congratulations to a proud, respectfull, and deserving new owner...Thank You for sharing Your excitement with the Universe!

[@SPDLTD]

One of my most common uses is calibrating my mics to the nearest gauge block size, especially in the sub 1" range. For example if i need to hit 0.8750 i will calibrate the mics to the .850 block to eliminate any screw drift from simply calibrating against the anvil at 0.0000" Handy little trick.

[@DavidKutzler]

Adam is a big man with large hands, yet, I'm always impressed that he has such a delicate touch when handling and using precision tools.

[@josephford8884]

And when he cleans a just-machined part. He's careful, he wipes parts, machinery, tools, and his big hands. Great stuff!

[@natedoerfler652]

This is the kind of learning that i come here for, thanks!!

[@garychaiken808]

Very nice. Use them well. Good information. Thank you 😊

[@broggyr]

I loved this demonstration and explanation. 👍🏻

[@CSWeldFab]

Great presentation Sir. I appreciate you sharing your knowledge.

[@stevenpressley5956]

Nice set. Thanks for sharing.

[@injoelsgarage3934]

Thank you Adam, congrats on the new set of gauge blocks.

[@RobertKohut]

I like "Tool Tuesday".... 🙂

[@silasmarner7586]

I like Shakespeare.

[@utidjian]

@@silasmarner7586 I like Emily Blunt.

[@danmetzger5583]

As usual, a great vid Adam. I am 8 years in now with your channel and treasure visiting you back in 2017. "Keep up the Good Work"!

[@RobertKohut]

I thought "huh, they are magnetic?" then you showed they were not, amazing!!

[@amalfi460]

If anyone deserves nice gage blocks it’s you brother…..they will be well cared for

[@tonyn3123]

I learned quite a lot about gauge blocks from this video. I am not a machinist, but the craft interests me. Thanks.

[@GeorgeWMays]

Extremely cool. Starrett is being a good friend to you. I really enjoyed the video. Thanks. It's appreciated.

[@mazchen]

And I see nothing wrong with that. This video is much more than just an "unpacking" or promotional video.

[@peteengard9966]

The shop my dad worked in did a lot of work for the arospace industry. They had Jo blocks calibrated down to the millionth. There were people from the division of weights and measures that would come to certify the equipment. White gloves were the only thing touching the tools. Nice set Adam. Should last you a lifetime.

[@douro20]

Any idea what the material was? The best are zero expansion ceramic or chromium carbide. Sets of Mitutoyo's "Zero Cera" blocks can be over $100,000.

[@peteengard9966]

@@douro20 I'm not sure. That was many years ago. My dad's been gone for twenty five years now. The shop was doing things for NASA and their contractors. They made some very expensive parts.

[@NotJRB]

Great video. Thanks!

[@Ro32da72]

Congratulations on your new set of blocks. Wringing has always just seemed like... magic 😂😊 and it's a pleasure to watch your excitement over your new tools.

[@tbernardi001]

The physics of "ringing" metal surfaces together is still not truly known. Some theorize that its an electron sharing on an atomic level that causes the bond. Nerds like me find it very interesting.

[@BrianFullerton]

Another theory I heard was that there is no room for air between the surfaces, so it is air pressure holding them together (acting upon the outer opposing surfaces of the blocks). Can't recall if this is BS or not...I seem to remember putting rung blocks in a vacuum chamber back in an engineering school lab. But I can't remember if they came apart or not.

[@martythezebra5183]

'wringing'

[@BrianFullerton]

I stand corrected: "wrung" blocks....

[@tbernardi001]

@@martythezebra5183 I, too, stand corrected. Learn something new every day, and it makes more sense, too. "Wringing" the air out of the space between the blocks.

[@martythezebra5183]

This community is so positive, I love it.✌🏻

[@cdrom1070]

i spaced the slats on my welding table for bolting and magnetic drilling. i restored a old set by using fine rubber abrasives and cleaning with a granite. they kinda wring and they read OK on a dial indicator. great spacers even though they look dodgy.

[@rizza7575]

You sir are a wealth of knowledge.

[@user-di7us4ni2p]

Mostly incorrect

[@Smallathe]

I love precision/machining tools too... Congratulation on the new gauge block set. Very cool!

[@user-di7us4ni2p]

What so cool about them, we’re they in the refrigerator

[@tcjatko7964]

In the USAF we used gloves when working with these.

[@jadesluv]

The USAF had multiple people working with the gauge block, had to keep the likelihood of smoker hands off them.

[@jerrydemas2020]

PMEL@@jadesluv

[@ProfSimonHolland]

very cool Adam, every Starret tool in my shop is a joy to use. they are well worth the cost, just for happiness they bring me, as well as their accuracy.

[@stevenslater2669]

Next question: How do they measure the gauge blocks to make sure they’re “perfectly” flat? Answer: Optical flats. Tom Lipton has videos in his KZbin play list explaining how you can make optical flats using the three-plate method. Surprisingly simple, but a very laborious process. I still don’t understand how they make the grinding equipment that grinds the blocks…

[@larshoneytoast722]

I was always taught to rub the mating surfaces of the blocks on clean paper rather than your hands due to the oils in your skin and also the heat from your hands causing thermal expansion (not relevant to open tolerance work but still good to know, I say) and it's always worked very well for me

[@PhilG999]

When I had my Metrology class in Jr College (late '70s) they had an old set of gauge blocks that had some corrosion on them from being handled and not cleaned afterwards. I was the only one in the class that could successfully "wring" them! 😁BTW, when wringing them you actually force (almost) all of the air molecules out and what makes them stick together is the atmospheric pressure on the end blocks. 🧐And as to tolerances, one of the best "slap your boss" stories I have is one time I made a part and the boss at the temp gig bitched about how "out of tolerance" it was! I pointed at the drawing he gave me and said: "A drawing with no tolerance specified is "assumed" to be +/- .001" and I am well within that."

[@musicbro8225]

I appreciate your speaking about caring for the precision tools. However obvious it seems it's good to hear a man excited about his new acquisitions talking about caring for his investment and considering the fact that precision is not a static or just a formality, it is influenced right down the line by the practices of every person involved in the job (accountability).

[@bulletproofpepper2]

I got my first gauge block set last year it was a smaller set. I used it to test my boss’s mic set, I think he dropped them. Thanks for sharing

[@davidhawkey8426]

I would love to see Lance come and inspect your beautiful new surface plate, just for the fun of it...just to compare his measurements to Starrett's

[@ClintsHobbiesDIY]

Nice vid Adam. I just bought a partial set of Mitutoyo blocks from your friend Jake today.

[@greghare4226]

Another thing to do is when someone is just coming into the trade learning to get a "feel" with measuring tools can be challenging. With gage blocks, knowing what the tool should read gives you a better feel for measuring and coming up with consistent measurements.

[@jcsrst]

Excellent point! Thanks

[@TonyHammitt]

Some follow up ideas: What do you look for in the calibration sheet? How do you adjust a micrometer or caliper? Are there some limits on how many blocks you should stack?

[@mdvener]

Very very nice.

[@KSMechanicalEngineering]

Nice work

[@TheTreegodfather]

@Abom79 Being in a coastal state like me, I'd recommend investing in some moisture dessicant packs. They're cheap as heck and you can leave a few in each toolbox drawer and in cases like that to have extra insurance against moisture. 👍 Congratulations 🎉

[@rodneywroten2994]

very nice

[@jasonhull5712]

Man them really nice. I don’t think I’ve ever bought or owned a set of anything new. Pretty sure every dang thing I own was second, third,fifth, tenth, god only knows how many hand.. lol I completely understand your excitement Adam. Especially you being a fourth generation machinist ! Haha. Darn near everything in your toolbox is handed down. Although I do believe that increases the value exponentially. But who doesn’t love being the first set of hands in a Starrett box ! No matter what’s inside! It’s Starrett !! 😊

[@antonekholm4642]

One really good swedish invention 😃

[@jcsrst]

Changed the whole game!

[@user-di7us4ni2p]

Nice blocks for a half set ,foreign blocks probably just as good

[@lundysden6781]

that was good.

[@randyfox4611]

TOOOOL TUESDAY!!!!!!!!!!!!

[@ClintsHobbiesDIY]

I just bought a partial set from your friend Jake.

[@angelramos-2005]

Congratulations on your new gage blocks,Adam.Mine are chinese.Excellent demo on how to handle and use the blocks.Thank you.

[@cmiller9800]

His are Chinese too. The block set he ordered was made in China but inspected at the Webber facility.

[@angelramos-2005]

Thank you for your info.Happy Holidays.@@cmiller9800

[@robjchristopher]

Be interesting to compare your Doall blocks to see how they are fairing

[@angelarichards3588]

Fabulous to be able to open them a just look and touch. I did notice that they didn't come with protective end guages though. Are they only provided with a A set,?

[@user-ze8ze3lj4v]

Тоже сегодня прикупил набор концевых мер длинны из запасов СССР. Достался не дорого - 15$. 2-й класс точности весь залитый салом без царапин. :)

[@steveNCB7754]

During my 4-year Apprenticeship (UK) in the 1970's, I spent a lot of time in Inspection and seriously considered pursuing it as my career. Sadly, there were no positions available when the time came to choose, so I went into the Design Office, where I got to inflict questionable tolerances on those with greater talent than me. 😇

[@CalibrationGuy]

I really enjoyed your video and your excitement opening your first new set of gage blocks. My only criticism is, not taking the deviation of each block into account for the final size of 1.9971. Starretts economy gage block sets normally run on the plus size. It was possible that the 4 blocks contributed another .0001. So now your zero set point is artificially high thus making your 1-2-3 blocks measure low.

[@emijoandrew382]

What cleaning reagent do you use for cleaning the surface block?

[@OO-xc7zg]

👍👍. Thanks 💥

[@floridaflywheelersantiquee7578]

Nice tools thanks for sharing

[@houndog7882]

Adam, I really like the way you take the time and o demonstrate and explain what you are doing keep up the great work.

[@patrickcolahan7499]

I recently purchased an older DuAll Gage Block set. Similar to yours. They need to be worked a bit as they will not stackup together. Would be great if you were to have an episode on how to do that. I have was thinking of using a coconut polishing cloth. Thanks for sharing.

[@tas32engineering]

To have your own gauge blocks is the pinicale. Pink granite surface plate is also quality.

[@thinkingmanhillbilly]

I was hoping they were going to be in a oak box with red velvet lining.

[@TedRoza]

G'day Adam. I was Impressed with your video on the Guage Blocks, & the comparison & measuring as well as the best way to assemble the guage blocks as an assembly. Well done, keep up the good work

[@mjwint]

As I understand it, the old Grade B designation is a closer match to the new AS-1. "Economy" is a step lower, and tolerance does not tighten as block size gets smaller, it is +/-50 millionths of an inch. Unless surface grinding these are a good block for general shop tolerance needs.

[@jamesagrinalds3111]

@abom79 I know that you take good care of your tools - if you are interested in selling your Do-All gage set, I'd be honored to buy them.

[@utidjian]

Very good presentation of the basics gage blocks Adam, thanks! Any plans for basic usage of gage pins, gage rollers and balls? Though they are small and pretty plain looking I have read that they are the most significant steps in creating our modern world of manufactured objects: interchangeable parts and consistent standards.

[@phoolb7326]

You could have also mentioned that the Cal sheet provided can make a set of "lower" grade blocks better by just correcting for the actual dimension via the Calibration report. A video to come?

[@waynespyker5731]

There is a cnc video on You Tube where the setup uses a gauge block for a toe clamp heel to machine a steam locomotive cover plate, the most expensive step block!

[@jamest.5001]

It wouldn't hurt. To cover that granite with pig mats, only uncover where you are working! To prevent butterfinger slip ups. It's easy as 1, 2, 3, block, crater!

[@gregdennis3523]

What's the going price for the set?

[@RayLautenschlager]

Weber is not that far from where I live. Thanks for buying Ohio again.

[@clintchapman4319]

I wish I could remember that little trick about how to choose which gage blocks to use. I know you mentioned it once on one of your videos, but I can't find it. Congratulations Bid!

[@NutjobGTO]

Sorry for the double post, but when you're wringing the gauge blocks together, you mentioned the extremely fine surface grind and cleaning the mating surfaces before you start. I wonder if it's an atmospheric effect, that you've squeezed out all the atmosphere and they're stuck together like a suction cup on a mirror. The only test would be to wring a set together and then put them in a vacuum jar and see if very low atmospheric pressure lets them fall apart.

[@silasmarner7586]

That's called "surface tension"

[@BixbyConsequence]

Gauge blocks will remain stuck together if placed in a vacuum.

[@karllautman]

Google "Van der Waals force."

[@NutjobGTO]

@@silasmarner7586 surface tension of the steel itself?

[@jamest.5001]

10:49 you do not want to wring them together in a vacuum, they can cold weld,

[@Stormin13]

Very cool - I wonder what physics is involved with ringing - surface tension?

[@test74088]

I believe it's atmospheric pressure. The block faces fit so perfectly together that air can't get between them and therefore no air pressure from the inner surfaces can balance the air pressure on the outside surfaces so that pushes them together. If the atmospheric pressure is 14 or 15 psi that means there could be 2 or 3 pounds of force holding them together. It's basically like a suction cup.

[@test74088]

I might be wrong since other comments are saying blocks can stay attached in a vacuum and that electrostatic or Van Der Waals forces might be involved.

[@millwrightrick1]

They do need a tiny bit of skin oil for them to wring together.

[@fairthorpefanatik1700]

At my previous employer, we had a granite surface plate. Some of my co-workers had no idea what it was for and thought it was to be used like an anvil, straightening bent parts by hammering on them against the surface plate, Bozos!

[@utidjian]

One of the first things you do (if you don't order one with it) is make a cover for your surface plate ;-) Even then it is still a horizontal surface and, as in most shops, the tendency is to pile stuff on it. I made a nice oak framed with plexiglass top cover for the one in my lab. Students and other people tend to treat things better when there is a nice container or cover for it. A sheet of cardboard or plywood will work but still collect junk and people may beat on it. When a surface is covered in glass (or even plexiglass) they tend not to drop things on it.

[@jcsrst]

😮

[@sylvaingervais247]

SALUT MERCI POUR TOUT CANADA QC.

[@daynosdr]

@Abom79 what are those pads you use. Uline?

[@steveh8724]

Pig mat oil absorbent pads. See Amazon, Grainger, etc.

[@braddobson2060]

Very nice but no wood box anymoe

[@JohnDoe-es5xh]

Hey Adam, keep these babies warm and dry, so they can't rust.

[@lerkzor]

Adam, a bit of trivia that you may not have heard - when you wring the blocks together, you are actually excluding air from between them, and it is literally atmospheric air pressure that is holding the blocks together. In space, since there is effectively no air at all, metals can become 'vacuum welded' because the two items get close enough to each other that they begin to share their surfaces in common. If I am wrong on any of this, I am sure that other commenters will be quick to point out my errors, with relevant links to accurate information. Anyway, hope you had a great holiday!

[@utidjian]

That trivia is incorrect. It is not atmospheric pressure because the holding force between two properly wrung gage blocks. Atmospheric pressure contributes to it but not significantly. Gage blocks also hold together in a vacuum when clean and dry. I have tested this myself. The majority of the force is molecular attraction (not magnetic and not vacuum welding.) The way Adam was wringing them there is also a very thin film of oil from his skin on the blocks which also helps but not in a vacuum.

[@wilfredr980]

I have seen a video some years ago. They tested the blocks in a vacuum chamber and they still stuck together, so vacuum isn't the holding force. I believe the conclusion whas that the so called van der Waals forces where the holding force.

[@lerkzor]

@@utidjian Thanks for the correction.

[@lerkzor]

@@wilfredr980 Thanks for the correction, now I have a new force to learn about :) EDIT: Interestingly, the wikipedia article for van der Waals force seems to focus mostly on liquids and gasses - but in the 'see also' section, the very last link is 'Wringing of gauge blocks'. That page agrees with your information. Interesting read, thanks again!

[@crossbowhunter9118]

Now you can buy a rack for the gage blocks buy a bore gage and use your new gage blocks to measure ID with a bore gage that is the most cost effective way to use a bore gage.

[@37yearsofanythingisenough39]

Better get a tube of Lanolube to go with them.

[@muk5production]

What is the air temperature at this room?

[@yohannwilkerson6058]

Less than the body temp of those fingers

[@EZ_shop]

Good video Adam, I enjoyed watching it. Are 1-2-3 blocks that are under size just as useful as the precise ones for work around the shop, or not? Ciao, Marco.

[@utidjian]

By "under size" do you mean that the blocks are no longer the dimension that is etched on them? How do you measure that? If a gaeblock no longer 'wrings' it is considered to be worn out. If it is off by a tenth or two it may be useful as a agage but then only to thousandth. Machinists often make Quick-and-dirty blocks of their own with dimensions stamped in them like 1/2", 1/4", 5/32" for example. They may be "gage blocks" but not Johansson Gage Blocks.

[@nickp4793]

@@utidjian He was asking about the 123 blocks that were re-ground to slight under 123. Not the gage blocks.

[@martinchabot_FR]

matched pair 1-2-3 block are useful for tool setup, like support a piece with two matched block. It doesn't matter if the 1" is off, but it matters that both are within tolerance

[@EZ_shop]

Thanks @@martinchabot_FR

[@pbrstreetgang2489]

Some gauge blocks when stacked can actually measure less than the individual blocks when measured separately...

[@jones7399]

yoo his intro music isnt only on the left side anymore!

[@avnsteve1]

"tolerance"

[@Paul-FrancisB]

"gauge" if you're English 😁🇬🇧

[@maddthomas]

I cannot afford a new set of Starrett or Mitutoyo gage blocks, I bought a cheap set for a little over $100 off amazon. Later I got a set of Mitutoyo set off Ebay for less than I paid for the cheap set, it was missing a 3 pieces but no rust, discoloring, dents or chips out of them...AND I had bought a dozen various size vintage new old stock Brown & Sharpe NIB gages that replaced the missing Mitutoyo ones. I did get new Mitutoyo and B & S Mics and calipers, those used Mitutoyo blocks measure within specs. I'm not bragging either, my friends and family don't understand why I was excited, they are used, however gently, but they are mine

[@g.tucker8682]

I get it :)

[@maddthomas]

@@g.tucker8682 most of them still had the preservation grease on them...

[@wallheadkdir]

So it's only to be used to calibrate your tooling in the shop....ooohhhkay

[@Cookerab]

Almost want to keep them in the plastic.

[@ramtinnazeryan]

Here is a manufacturing question. Would it be possible to get a third party calibration certification on your reference gauge blocks and calibrate the rest of the measurement tools in house? Wouldn't be more cost effective?

[@Bancroft12194]

Yes, sending even a full set of gage blocks out for calibration isn't terribly expensive. But if someone isn't skilled/trained to know the proper way to calibrate certain tools with them then you could just be introducing error into your tools unintentionally. Your customer may ask for what "qualifies" whoever did the calibration in house to do it. Sending to a third party usually comes along with ISO/NIST credentials to back up their skill level so your customer is happy.

[@Renville80]

Best practice is to keep one set in a controlled environment and only use it to validate your ‘main’ set of standards and measuring tools. Don’t even use them for inspection, only use them for comparison with your main standard set, and it is that ‘primary standard’ that gets sent out for certification with traceability to NIST.

[@stuartschaffner9744]

This was fun. I'm certain that you are following all the rules, but I have some questions. First, what kind of steel are your gage blocks made of? Do they flash rust if the oil layer is removed and the humidity is high? What about oils and acids from your hands? Also, what about temperature? I guess that a thin block would be relatively independent of temperature, but how about those 3 and 4" blocks? Would you need sometimes to wear insulating gloves to avoid transferring body heat?

[@user-ze8ze3lj4v]

В инструкции к КМД СССР написано, что их длина точна при 20 градусах Цельсия. И есть коэффициент теплового расширения стали для других температур. За тёплыми пальцами нужно следить :).

[@millwrightrick1]

Depends on the grade of the blocks. The highest grade are stored and used in a temp controlled clean room just so variations in dimension are minimized. Adam's set is B grade and accurate enough for use on the shop floor.

[@emilgabor88]

For example, it’s OK, but you need the indicator to be at least 5 times the resolution you want to show. So for 0.001 tolerance you need a indicator whit a resolution at least 0.0002. I have worked six years like methodology expert . This is how in Europe is… 95% sure that in US is the same

[@hansieveldsman8553]

10 years back i verified weighing scales and we had to go up in 0.2 of a division. To determine the error. That works out the same as 5x resolution. Is was in south africa so i think its a global standard for measurement.

[@utidjian]

That would be the case if checking the accuracy of a gage block. To check a gage block against a master set of gage blocks he would need a lab-grade set (Grade AA or B89) and optical flats with a monochromatic lamp. For checking as he did for some shop made 1-2-3 blocks his tenths indicator is fine. Note that he was checking for +/- 0.0001".

[@emilgabor88]

@@utidjian yes and no. By comparing gauge blocks you need that the indicator to be at least five time the maximum error four that gauge tolerance. If the gauge has for example 0.0001 tolerance, you need a indicator 0.2 of that division . You can’t measure 0.001 precision whit an indicator whit 0.001 division because the indicator has probably a 0.001 tolerance . Did you understand?

[@utidjian]

@@emilgabor88 Ah I think I see the confusion. For one thing, Adam is NOT comparing two gage blocks in this video. He is comparing a stack of gage blocks to a block that he made and someone else finished. He is using the brand new grade B gage blocks as a standard to measure one of the dimensions (the nominal 2" dimension) on a nominal 1-2-3 block that he made. When he measured the nominal 2" dimension with his tenths reading 2-3" micrometer it was 1.9971". Then he measured the stack of gage blocks and got the same reading (1.9971"). What can you confidently say about the accuracy of the stack of gage blocks, the accuracy of the nominal 2" dimension of the 1-2-3 block, and the accuracy of the micrometer he used? He then zeros the tenths reading DTI on the stack of gage blocks and then slides the nominal 2" surface of the 1-2-3 block under the DTI. He doesn't get a zero but it is one division off (0.0001" under.) What can you confidently say about the accuracy of the stack of gage blocks, the accuracy of the nominal 2" dimension of the 1-2-3 block, and the accuracy of the DTI used? Now... IF he was trying to measure his old second or third hand gage blocks that his grandpappy used what is the best he can do with the instruments he demonstrated in the video? What is the *tolerance* can he measure the old gage blocks to?