Origins of Precision

Please support me on Patreon

This is the first video in a series of recreating the first micrometer. Before I introduce the project, I look into where precision comes from.

Please Like, Share and Subscribe

One clip was too expensive to license, but you can view it on my website.

Licensed under Creative Commons: By Attribution 3.0 License

[WilliamEades_Frostbite]

At 18:15 you state that it's unknown why gage blocks ring together. I was a NBS Physical Dimensional Laboratory Supervisor and Tech who used them almost daily during calibrations. The reason they "Stick" is from Molecular Adhesion. The lapped surfaces are so flat that adjacent molecules in rung blocks begin sharing valence electrons. This action causes them to stick together. An interesting aside is that if you leave two blocks rung together for an extended period, they will "Contact Weld" and you will never get them separated. (I had a trainee totally ruin a part of a set when he left the stack rung over a long weekend)
Something I saw you do that should be avoided is your handling of the blocks with your bare hands. Gage blocks are 316 Stainless, and your body acids will attack the lapped surfaces. Prior to use, you should always clean the blocks with Acetone or MEK and afterwards fully reoil the blocks using acid free block oil before storage. I would tear a tech a new one if I caught him handle blocks without wearing linen gloves. Also S1 Standard blocks are calibrated for use at 68F + or - 1 degree with a correction factor of +/- 11 microinches per inch per degree deviance off nominal.
(He steps off the soap box) ;-}

[bhgtree]

'The problem is that your barleycorns may be a different size then mine or mine might even dry out and change over time.'
---Every man's constant worry.

[brushybillroberts]

As a Journeyman Tool & Die maker with 47 years in the trade, I found this fascinating. Too many of us take the surface plate and Jo-Blocks for granted. I made a set of flat lapping plates as a student at the age of 17. (three plates lapped together just as you described) I still have them in my tool box.

[rompis.a]

When I was little, I used to wonder: If factory equipments were made in another factory, how was the first-ever factory built?
More than a dozen of years later, I get my answer in this video.

[Yourname]

I always wondered how you can make precise tools from the absence of precise tools, but now I know: rubbing 3 flat surfaces together to make them extremely precise. Neat.

[von...]

This video is being played as a part of Harvard's Introduction to Materials Science and Engineering (ENG-SCI 190) courses now.

Big ups my dude, I would be speechless if I found myself in your position. Make sure to use this as a bragging point as needed.

[kushalpatel]

In my 4 year of bachelor degree in mechanical engineering, I had never been gone through this history of precision so it very fruitful for me to understand the ground level of mechanism to advance level, thank you so much

[dewiz]

Who would have believed, that at the age of 74, I would have my mind blown! Wow! Thank you very much!

[drewgoddard]

A beautifully put together piece. I've worked in engineering for 30 years and I had no idea about some of this stuff. Very glad this popped up on my suggested videos. Thank you 😉

[firennice]

This is fascinating. I work for Sandvik, doing inspection. Where the blocks, pins, etc come from that help gage our machinery into the millionths of an inch.

[eclew]

I've wondered many times how precise machining and measurements we're made back in the days. When you mentioned C E Johansson I recognised the name and googled it. Turns out that the factory where he first made the measuring blocks is the beautiful old building visible from my living room window. What a funny coincidence!
Thank you for a very informative video, I knew he was known for making tools but I did not know the significance of his invention.

If someone's interested: The factory was built in 1813 and is now a museum mostly dedicated to Eskilstuna's technical history. There are still some houses preserved that were used for making guns, built all the way back in around 1650. I really need to learn more about my city's proud industrial history!

[BAgodmode]

Precision was invented when John Precision accidentally did accuracy twice.

[michaelcagle]

Answered questions I've had since childhood. I remember asking my dad how we got the first straight line. He was very honest about it. He didn't know.

[shockingguy]

This should be required learning for anybody going into engineering of any kind This was an absolute joy to watch thank you

[BodyKnight]

When i first herd about the three planes method i was blown away. I had always thought that precision was something which emerged slowly, through history, a conquest gained by mankind literally a fraction of unit of length after a fraction of unit of length. But the fact that no, you can just make something flat out of nothing, and then derive practically everything from that reference thing - is so unbelievable. It's one of those things in science that looks like when you can see three's roots under the asphalt, like if there was a pattern and sometimes it's on the surface and it's easy to spot.

[jmaverick]

I'm retired now, but I spent nearly 45 years of my life in the machine trades. I've been fortunate enough to operate many of the machines you have described here. I served my apprenticeship at Westinghouse Electric's main manufacturing plant in East Pittsburgh, Pennsylvania. It was a great program, but unfortunately nowadays there are very few apprentice programs in the machine trades and the high schools have all but eliminated the shop classes where I first became interested in metalworking. During my career I was a job shop machinist/ quality control technician/ toolmaker/ and master toolmaker. It was a very satisfying career that educators and guidance counselors seem to have forgotten about. You have an excellent channel here and if you haven't already may I suggest a trip to the Henry Ford Museum/ Greenfield Village in Dearborn and maybe a trip to the metalworking museum that I believe is in Vermont.

[kristofferbook]

As a Swede I feel proud, but also a bit sad Mr. Johansson is not given the credability today. I humbly bow my head and send him warm thought.

[jayying]

Even as a 2nd generation machinist with over 10 years in the industry plus the trade schooling and apprenticeship and relevant experiences and skills... I cannot believe I never realized the role and importance of the surface plate, which I think I have probably used the most versus any cutting machine or tools. Really opened my eyes a little bigger and really appreciate much more in this amazing field that I'm in.

[Nighthawkinlight]

Really phenomenal video. Enjoyed it greatly

[blueguitar]

I was a Navy Metcal program technician and lab manager. When you said surface plate I was like, where’s your metcal tag? AND THERE IT WAS!!