Thank British eggheads for Apple’s new iMac’s sexy seamless knife-edge

“A little-known British company is the brains behind technology in the new super-slim iMacs that Apple CEO Tim Cook raved about on stage,” Anna Leach reports for The Register. “That admired tech is the tapered aluminium edge at the 5mm-wide end of Apple’s latest thin desktops, which were revealed at an event in October.”

“The welding technique that has made the new iMac so thin is the intellectual property of Cambridge-based company TWI,” Leach reports. “The Apple iMac is just 5mm thick around the edges of the display on the all-in-one computer, and the aluminium join is made possible by friction-stir welding.”

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Leach reports, “Invented in 1991 by Wayne Thomas at TWI, friction-stir welding is a solid-state process, meaning that it doesn’t require the materials to be melted for them to be joined. Instead it softens and merges the edges by mixing the two materials under frictional heat… Apple licensed the tech earlier this year and has been testing it since then. Iain Smith, associate director and intellectual property manager of TWI, would not reveal the commercial details of the deal with Apple.”

Apple's all-new iMac (8th gen)
Apple’s all-new iMac (8th gen)


Read more in the full article here.

Related articles:
The Verge hands on Apple’s new iMac: Extremely thin, stunning – October 23, 2012
Apple unveils jaw-dropping all-new iMac – October 23, 2012


  1. Between Jony Ive, ARM processors and now this it’s obvious that England is gradually taking over Apple from within. Give it another decade and the company will be based in Stratford-upon-Avon, everyone will break every day at 3pm for tea and scones, and cricket will be mandatory.

    1. “the old friction-stir welding trick”, yup, and by old, we can say for sure it is over a half century old and been used many ways.

      Spin welding was used to join circular plastic parts which is over a half century old, and it was used before that to weld metals, too, in some special cases.

      Then after WWII a big jump was the commercialization of multi-kilowat ultrasonic transducers which could vibrate plastics at 20 kHz to create frictional heat and bond two plastic pieces together reliably.

      I would not be surprised to find out that the “friction-stir welding” used ultrasonics. Electromagnetic induced infusion seems unlikely given the conductance of aluminum, though I obviously guessing on this.

      So the Brits are doing what inventors do worldwide in pushing the state of the art.

    2. Friction-stir welding has been used on spacecraft (e.g., Shuttle External Tanks), too. It is particularly useful when the alloy to be joined (such as the aluminum-lithium used for the Shuttle Super Lightweight Tank) would could not be processed using standard welding techniques. A rotating mandrel is driven through the material along the joint and literally stirs the two pieces together across the clamped joint. This technique also involves less heat, which can be useful in preserving the material properties of heat treated alloys. In the process that I saw on video, a plug was inserted into the hole that remained at the end of the girth weld. The plug was stirred into place and then machined flush.

      I am no expert on this technique. But it is very cool and you should take a few minutes to check it out. I never expected it to be used on a computer. Not surprisingly, Apple is the only computer company that cares about design enough to explore cutting-edge manufacturing techniques. No one else is close to Apple’s unibody chassis.

        1. Glad to help, Micro Me. This forum is intended to exchange ideas, extol or denigrate existing Apple products, speculate on future Apple products, and disparage Microsoft, Samsung, and Google.

          I’m sorry that I didn’t catch the Maxwell Smart reference. I am old enough to have watched more than a few episodes. But that was a long time ago…

  2. Ok, I’m as much in love with Apple’s industrial design as anyone, however, why on these machines would you put the SD Card slot at the back? An uncharacteristic mistake that makes inclusion of this feature practically useless. You blew this one Sir JI!

    1. Yes, I absolutely agree with you: Form over function. Apple could provide a built-in SD card reader for peanuts. Now if we want that sort of functionality, users have to buy an external accessory that will cost thirty times what users paid extra when it was a standard feature.

      I should think that a huge percentage of Mac users used the SD card reader.

        1. Yes there is. However the point being it is on the back. How are the majority of people going to access it? Having a feature that is not usable is no better than excluding it. It was a very bad decision assumingly made so the look of the machine would not be “impaired”. But practically once more, when you’re using the machine, you are not staring at the razor thin profile.

      1. And there you go… Point missed entirely. Yes, you CAN work around it by cabling in to a USB port, but then why bother having the built-in SD Card reader in the first place? May not be a”big deal” to you, but what if all you have is the SD Card, no camera or you don’t have the cable for the camera? The original comment is to highlight a very impractical call made by Apple to put a feature in a functionally inaccessible location. What would the opinion been had the optical drive slot been on the back?

        1. “May not be a”big deal” to you, but what if all you have is the SD Card, no camera or you don’t have the cable for the camera?”

          OMG, I had to plug my SD card into the BACK of the machine! That certainly qualifies as an FWP.

          1. Have you ever tried to plug something in sight-unseen? A small SD card into a thin slot on the back of the computer? Sure, it can be done, but not without a little trial and error. Multiply that by the thousand times I’ve used my SD card slot and it becomes a bit of a bother. Not necessarily a deal breaker, but something to consider.

            And ‘FWP’? Why use an acronym that means nothing to most people?

        1. Well, since all machines that have a card reader currently have it on a side of the machine, we’ll have to wait until you actually have a machine where the slot is now at the back and then revisit your comment.

        2. The difference being all those other slots in the back have a cable plugged into them and then are left alone, whilst the hard-to-reach SD slot also in the back is expected to be used on and off, over and over, today and tomorrow…

      1. Yup. I love and use all my Apple stuff but………….. I’m no apologist. Apple does what Apple does because it benefits Apple not always the consumer. And that’s okay, they’re in business to make money. But there’s not much choice out there. After 30 years it’s too late for me to start using a PC! And personally I don’t care how thin the screen is on the iMac. I have the current version of the 27 inch iMac and it’s just fine. I’m thinking of getting a new one because I’m not crazy about the current screen. I believe the new iMac has the antiglare screen. Which does make a difference. But you can’t order it yet. I wonder if you can order it on Thursday?

      2. We covered this when the new iMac was announced, art2arch. The perforated RAM panel moved from the bottom to the back, just underneath the hinge. RAM is still user upgradeable. Don’t spread FUD through ignorance.

            1. Apple knows you don’t want the 21″
              if we want to be crybabies, let us cry over card format. all my cameras, of course, use CF. only chumps need SD.

  3. I hate that thin edges crap. It’s deceptive. Makes you think the whole machine is really that thin until you actually see it. You can’t find one picture of the iMac throughout that shows its true profile.

    1. The volume of the enclosure was reduced by 40%, if I recall correctly. That is significant.

      And it is worth noting that Cook turned the iMac 90 degrees to show its true profile during the media event. It is a bit deceptive, but not egregiously so.

  4. IMHO, the “virtue” of a 5 mm-thick edge isn’t worth the loss of a Superdrive and a memory card reader. I couldn’t be happier with my custom, build-to-order 27-inch iMac with i7 processor.

    Notwithstanding Apple’s vision that all software will be downloaded from their App Store and disks are not necessary, I need optical disks often enough.

    And the memory card reader makes it so I seldom bother to hunt for that custom USB cable that comes with digital cameras; I always just pop the card out and plug it into my iMac.

    Now when users need that functionality, they’ll need to make it a USB 3.0 or Lightning accessory. (*sigh*)

    Just because Apple calls it “progress” doesn’t mean it necessarily is.

    1. Just because you don’t call it progress doesn’t mean it isn’t. And since Apple has won numerous awards for their products, I’m more inclined to take Apple’s word for it.

      I use USB thumb drives all the time (I’ve never used an SD card) and it is not that difficult accessing the rear of the iMac… it rotates rather easily.

      The loss of the SuperDrive is unwelcome, but I’m guessing Apple’s thinking here is the opposite of what you think… The SuperDrive was going anyway as it has in all of their other products. With the SuperDrive gone, it gave them more freedom in the design. DVD drives are extremely cheap and OS X allows you to access the DVD drive of another Mac on the same network, so there are workarounds.

  5. it does not surprise me for 2 reasons:
    1. Brits are the most creative “ethnic” people in the world, i’ve seen it countless times as i traveled/lived/worked around the world, and they care creative in most fields, and long before the Industrial Revolution that the Brits launched, not the Germans or French:

    Britain’s human capital advantage was always it, giving birth to a concentration of “tweakers” more than anywhere else, as economists Ralf Meisenzahl + Joel Mokyr explain: the UK was fertile for “micro inventions necessary to make macro inventions highly productive and remunerative.” (read New Yorker article 2012 Nov 14 “The Tweaker” by Malcolm Gladwell

    2. we Americans, supposedly, the inventors of the world, though only in the last 236 years, have fallen asleep and lost our visionary “american excellence”; anyways, it’s all good, as it exposes our arrogance and gives us the chance to reboot our country to think again, think differently rather, as Apple has been all along ; )

    1. rolf, your opinions are just your opinion but a good observation. However, America is a place where all good minds seem to go to make great things, foreign or homegrown. This is backed up by NASA, Apple, JPL, MIT, individuals, and many others. The people that work here are from all over the world and mixed in with good ‘ol red-neck engineering, great things do happen.

      1. This is definitely true. Brits come up with so many great ideas, but it nearly always takes another nation’s hand to turn that idea into something worthwhile.

        Great at inventing, but utterly pants at management. That’s us.

        1. Yes a good point here. At the top we are superb even the Germans respect that as I found talking to an engineering post graduate here on a 12 month release however scaling it up is our great problem and the American (now Asian) specialisation. We were born on invention and innovation, sadly hat is now only a shadow of what it once was. 20 years ago it was estimated that one third of all American wealth relied on Scottish inventions alone.
          As one example of taken for granted innovation all modern aeronautical bonded materials originate from the work carried out by DeHavilland on the Mosquito and Hornet and the family still had time to provide you with 2 of your greatest actresses too. Yep no end to he talent just a lack of support and finance for it which is why so much of it does indeed end up abroad.

      1. I’m with you there too, 27″ for me… my 2006 24″ iMac showing its age. Don’t care about Optical Drive, got external for forty bucks but only used a couple times for my MBAir. The SD, never used. The current models are nice, but waited so long for this new update, it’s now a quest to obtain! Hope it won’t be long now. Any further delay and I’ll go bonkers…

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