Machinist Magic: Gauge Block Wringing

In this age of patent trolls and multi-billion dollar companies that make intellectual property claims on plant genes and photographing objects against a white background, you’d be forgiven for thinking that a patent on a plain steel block would be yet another recent absurdity. But no – [Carl Edvard Johansson] got a patent for his “Gauge Block Sets for Precision Measurement” in 1901. As [AvE] shows us with a video on how gauge blocks can be “wrung” together, there’s more to these little blocks than meets the eye.

Gauge block wringing is probably nothing new to experienced machinists, but for the rest of us, it’s a pretty neat trick. To start the show, [AvE] gives us a little rundown on “Jo blocks” and what they’re good for. Basically, each block is a piece of tool steel or ceramic that’s ground and lapped to a specific length. Available in sets of various lengths, the blocks can be stacked end to end to make up a very precise measuring stick. But blocks aren’t merely placed adjacent to each other – they physically adhere to each other via their lapped surfaces after being wrung together. [AvE] demonstrates the wringing technique and offers a few ideas on how this somewhat mysterious adhesion occurs. It’s pretty fascinating stuff and puts us in the mood to get a gauge block set to try it ourselves.

It’s been a while since we’ve seen [AvE] around Hackaday – last time out he was making carbon foam from a slice of bread. Rest assured his channel has been going strong since then, with his unique blend of laughs and insight into the secret lives of tools. Definitely worth checking out, and still skookum as frig.

86 thoughts on “Machinist Magic: Gauge Block Wringing

  1. Many young metal worker have ruined their just finished workpiece by putting it’s perfectly flat surface on an also perfectly flat marking-off table.
    Afterwards, you can’t remove it, without bending it.

    This also happens to flat glass surfaces, especially, when they’re wet.

  2. I first learn’t this in BTEC L1, the college had a set of these gauge blocks through years of student abuse, etc.. and they still stuck together this way when I was being lectured.
    Also we were told these blocks are ground not only to a given length, but to a high precision flatness as well.

    I later found most HDD platters do the same thing when their surfaces are pressed together (glass laptop HDD platters stick better in my experiences so far).

    1. maybe interesting tidbit: early HDD platters had to be made artificially rough by additional chemical etching process to fight sticking of parked heads during prolonged non use.
      IBM was first to invent plastic parking ramps for Heads in early ~2000. This not only made disks more durable, but also allowed for higher capacity disk surfaces.

      Hope my link doesnt land this post in spam.

      1. In the early 90’s I had a bunch of 4GB IBM drives in a RAID system that was temporarily turned off to move some stuff around, and they got into “stiction”. Was on the phone with an IBM guy and he was telling me to bang the drives on the edge of my desk to unstick them. I’d bang them, try it out, still no go, he’d say, “Bang them harder!”. “Really?” “Well, it already doesn’t work, you can’t break it more.” “Ok.” So I’m sitting there slamming these expensive 4GB hard drives with critical data on them against the edge of my desk while management looks on. BAM! BAM! BAM! Got enough drives working by slamming them into the edge of the desk to get the RAID array back online and backed up. Man that was super stressful at the time, but looking back it’s kind of hilarious. On that day I was Fonzi.

    2. I also suck hard disk platters together.

      But that’s not how I ‘invented’ the technique. I found out about it with glass flashlight/rotch windows that were perfectly flat. When thoroughly cleaned, they would rub together, and at the bonding spots the transparency would go up (looks darker because of missing internal reflections) and just around the bonding spot there are rainbows visible (diffraction patterns).

    3. I also stuck hard disk platters together.

      But that’s not how I ‘invented’ the technique. I found out about it with glass flashlight/torch windows that were perfectly flat. When thoroughly cleaned, they would rub together, and at the bonding spots the transparency would go up (looks darker because of missing internal reflections) and just around the bonding spot there are rainbows visible (diffraction patterns).

      1. there must be some people with a genetic defect that causes their eyeballs to implode and their eardrums to burst if their hear or see the word fuck, that is the only rational explanation for it being so important to avoid

        1. Not really. Like any condiment they have to be used sparingly. A well-placed invective can be both appropriate and entertaining, however overuse is both lazy and diminishes its impact.

      1. It’s not unreasonable to expect people to go easy on the obscenities on a science related website.

        Stop using the hollow term “safe space” as it is used to legitimize ignorant bullshit opinions instead of words that are relevant to a discussion.

        1. “Obscenity” is nonsense. There’s no logic behind it. Why is “fuck” a “bad” word but “copulate” isn’t? Neither is “duck” or “truck”. It isn’t the meaning, it doesn’t appear to be the way it sounds. Why do newspapers print “f*ck” and that’s somehow OK even though we all know they mean “fuck”? Is it like a magic word, that invokes an evil force?

          Seriously. The logic behind a taboo on some words completely eludes me. Seems like one of those thousands of things people just do because everyone else does, and everyone else does it because everyone else else does. Stuff like that pisses me off. The human race is illogical and fetishistic enough. A bit of logical consistency would be nice. And if I expect to find that anywhere, it’d be here.

          1. Taking it further, what gives *any* word meaning at all? The tone and method of conveyance can make a difference and how people respond to a word can make a difference but fundamentally, why are certain combinations of letters perceived as obscene while others which explain the exact same thing are seen to be more socially accepted? Although, it can all depend on the context of the situation as language between friends could be saltier than language in public but this too depends on other factors. Education, the time of day, specific setting, etc. Amusingly, these and other noteworthy elements of language and culture have been studied to a degree.

            “According to a scientific study, intelligent people use more swear words.

            Researchers at Marist College in New York say a big vocabulary of curse words is a sign of higher rhetorical skill, and those that can name the most swear words in one minute tend to have a greater overall vocabulary.

            These findings challenge the stereotype that people curse because they can’t find more intelligent things to say.”


          2. Internet, the thing about swearing being a sign of low intelligence is simple snobbery. Middle-class people swear less, and like to think their station in life is down to their superior intelligence. It really isn’t. I’m smart as fuck and I swear like a cunt, and I’m common as shite.

      1. Sorry, I’m with Alan here. I would feel very embarrassed to watch this with family around, young or old.

        It’s long been a tradition in the geek community to NSFW tag things. Why not here?

        Thankfully I’ve already seen enough of Ave’s vids to know they’re not worksafe.

        1. No it hasn’t! “NSFW” is a corporate, office-environment thing. Geeks have never given a shit about that. We’re irked to be out of our caves in the first place. Worrying about social etiquette and it’s enforcement has never been something I’ve seen a geek do. It’s practically the opposite of the definition of “geek”.

          1. eh? I remember first coming across it on david evnull’s column in PCW about furries in the early 90s before “the internet” was really a thing in the UK, so I assume that it was in existence before then. (he had an xmission email address, so the article must have been around 94ish)

    1. AvE is heading down the path of ‘the more I swear the funnier I become’. His videos, while interesting and amusing, are becoming harder to understand due to his choice of words and more crude.
      The videos are becoming better made, contain better researched and more interesting subjects so hopefully a balance will be found between the language(not just the swearing) and the content.
      He’s going from ‘always good to watch whenever there is time’ to ‘good in small doses but it quickly becomes too much’.

          1. Anyone that has spent any time in a machine shop knows that the language used therein is often colorful – but then again those that have spent any time in a machine shop know how to wring a pair of gage blocks. One would assume then his target audience are those outside the field and consequently he should be presenting to this larger audience. The sort of language he is using does nothing to dispel the myth that blue-collar skilled workers are uncouth and uneducated, when nothing could be farther from the truth.

          2. i would say the perfect way to dispell that myth is to uncouth and educated and he does seem to fit that bill rather well.

            perhaps the people that truly believe and perpetrate that would simply find someone else to be superior to once the blue collar worker wasnt an acceptable target any more?

          3. And? I still don’t think this sort of language adds anything of value in this instance, nor does it place anyone in a good light. It may be stupid, but you will be judged in a negative way by many and some of them may have a broader impact on your life. It’s just wiser to control yourself. When I was in industry I saw guys passed over for promotion to management more than once because it was felt that their salty language, quite acceptable on the shop floor, would not be in the office.

          4. Indeed – I’ve worked in many environments where ‘sewer-mouth’ is the norm and is accepted as such. Doesn’t mean I must enjoy it or join in. If that’s the way someone chooses to speak, so be it. I believe it adds no value at all, but it does reduce their potential audience in exchange for questionable (if any) gain.

        1. Have you seen youtube’s comment system of late? Unless you post in the first few seconds of a video everything vanishes into the noise especially on the more popular channels except the ‘thumbs up for no reason’ comments
          At least here there tends to be some discussion and I can find out if I’m the only one with this view, if only a few points resonate and I’m partly wrong or if I should shut up completely and let everyone else enjoy it.

    2. I’m more put off by his insistence on trying to be funny. The language he uses and his mannerisms all reek of someone who tries too hard for people to find him amusing. It’s a shame because he’s clearly very knowledgeable and looking at his other videos he has a lot to offer.

    3. Perhaps you should change your name to Alan Ivorytower, Seriously if you can’t handle a couple of swear words I really don’t think you are adequately prepared for the real world. “Swear” words are just words, A word is just a formation of letters that have a meaning he didn’t call you any of these swear words so why does someone else’s language choice bother you so much? I may have understood it he called you personally a “fucking douche”.
      If only ISIS could see how upset at people get from others dropping F-Bombs perhaps instead of trying to kill us they would run into shopping centre’s shouting obscenities instead.

      1. When your content starts to be keep ya dick in a vice an fuck every 15 seconds it gets old pretty soon…
        I have been watching him since the start of his channel, and you can go back and see that he might show some nicer toys in the videos, but the swearing is getting a bit in the way. That and I imagine that half the content is behind the Patreon thingy, I’m already white listing who I like in my ad-blocks, I might do donations, but I wont pay monthly, sorry…

        1. Actually, no there is not much content from AvE that is for donors only, he posts on YouTube almost daily but last video on Patreon is from June or something. I do enjoy his videos, i guess i just don’t notice whatever words are offending some people here. I sure notice anytime my teenage daughters use bad language, but any attempts at censorship from my part wont stop them from learning that, instead i teach them that lack of vocabulary or ability to express oneself only make you sound unintelligent, so use it with friends who knows you already, and not when making first impressions. I know AvE is intelligent and knowledgeable, and in the early beginning he used a very “clean” language, then he made one mistake had got the shitstorm for it, so he said “fuck it” this is my shop, you are my guests, like it or leave it…. That said, i do agree that his content has started to go a bit more gonzo lately, but i still enjoy it.

        2. I can see why it may grate on some people but warnings about swearing in video’s shouldn’t be a thing. You are right he does use “keep your dick in a vice” a lot but he is trying to be memorable. quite a few Youtubers have a sentence or two they say in nearly all video’s.
          I am pretty much the same as you when it comes to Youtube ad-block everyone but if I regularly watch a channel I whitelist them too. I haven’t donated to Patreon accounts before I think I would only consider doing this if a channel promised to make or do something I was really interested in and I wanted to help fund it. The way I see youtube is they get paid through ads (that I watch) they knew this when they signed up so I don’t feel obliged to pay them. That is not to say I am against Patreon I think if people find content they want to help make better go for it, Just not really my deal.

          +1 AvE

      2. It is not the swearing that causes the problem, so much as the overuse of the words. At least personally, I am slightly offended by the word but more so by the fact that words are being inserted where they serve no purpose. Used sparingly, they can be used to provide emphasis. For example “hard as fuck” on the testing block means that it is harder than you would assume hard to be. In this situation it makes sense, though for anyone experienced enough to use a testing block probably knows this already. There language choice bothers me because it is like having a bright light shone in my eyes, or being served a meal that is covered with salt. Used in moderation it is beneficial however used to the extremes it is garish, and yes, offensive.

        1. as with many things it is a matter of perspective.
          most closed social groups show some sign of social inbreeding, if rough language is used that effect can completely change what is and isnt normal or acceptable.
          from some of the references he has made i gather that he spends or have spent time in mines and similar industrial environments, in some of those settings his language would be considered tame, his videos certainly hasnt helped but iw ould be surprised if he didnt have it from somewhere.

      1. It’s an example of the horseshoe phenomenon, where the extreme left and right start to resemble each other worryingly. Both can have the Puritan “We know what’s best” mindset, treating those who disagree as naughty ignorant children.

    4. Frankly, a “Disneyland only” language warning is even nicer. I’m a big fan of real conversation, and that means one human sharing with another.

      “You gotta piss with the cock you got.”

      Golden. I would have a beer with this guy anytime. Count me a fan.

    5. I still don’t understand that people can say kill, but not fuck, massacre, slaughter. all ok, but dare you if you use some sexual words…

      we still have a long way to go

  3. I just discovered Ave accidentally a week ago and he reminds me about a machinist I knew once, also swearing all the time and pushing his tools over the limit and more swearing.

    1. Try Ashens. He sounds like a smug ’70s local radio DJ, with swollen adenoids. I really can’t stand listening to his fake-mateyness, makes me want to strangle kittens.

    1. We could test the effects of air pressure by putting some wring’ed blocks inside of a vacuum chamber and then evacuating the air. Looks like a decent vacuum chamber with clear sides would only be around $100.00, so the experiment wouldn’t be too pricey.

  4. So is there a prevailing theory on it? I’d think some kind of metallic bonding thing, except it works for ceramics. Smoothness is important.

    Feynman is quoted in this ^ article.

    Ceramics are often metal oxides, but not always, but wouldn’t the oxide prevent the usual inter-metallic bond? I’m a bit beyond the edge of what I know about that subject here. Does it work on non-metal ceramics?

    Could it be simple static friction, where the smoothness means lots more atoms get much closer to each other, than if there were tiny bumps and scratches increasing the distance between the surfaces? Or something to do with gecko feet which use Van Der Waals forces?

    1. When I was much younger and at the Henry Ford museum in Detroit, the explanation on the card said that the blocks undergo spontaneous welding.

      Microscopic imperfections in the smooth surface are viewed as “mountains” that have extremely small contact points at the tips. When the two blocks come together, the force per area of contact is enormous – high enough that the mountains spontaneously melt and flow while the blocks are pushed together.

      This doesn’t explain why the blocks can be slid across each other, though. I wonder if after they’ve been wrung together it’s harder to twist them apart than it is when they’ve been twisted together.

  5. I worked in a precision grinding shop 38 years ago, and we never once used oil on the gauge blocks. The gauge blocks stayed in a temperature controlled room that was cleaner than any other place in the shop (that’s not saying much, but at least the air came from the office HVAC system, and wasn’t recycled oily shop air.) Once every few years, they were sent for certification (probably when the boss got a contract stating high precision with traceable standards.) We cleaned them with a buckskin chamois, then wrung a stack to the desired size. There were certain blocks that had been scratched (seemed like it was the 0.5000 inch block) and wouldn’t stick, so we’d have to stack up a 0.200 and a 0.300 to make up for it.

    We always assumed it was simply air pressure holding them together, and never thought it could be “atoms sharing electrons”. But if you needed a couple of thin ones stacked on top of each other, and they wrung well, they were sometimes a bitch to separate.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.