Home American Brand Padlocks (128) Correcting Master Lock’s Design Change on the American 5200 Series Padlocks

(128) Correcting Master Lock’s Design Change on the American 5200 Series Padlocks


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My vises are made by Panavise, a U.S. Company.  The one with the wide jaws is the model 350.  The smaller one is the model 301. Both have the 312 Base mount – www.panavise.com



  1. Wonderful goods from you, man. I’ve understand your stuff previous to and you’re just too wonderful. I actually like what you have acquired here, certainly like what you are saying and the way in which you say it. You make it entertaining and you still take care of to keep it wise. I can not wait to read far more from you. This is actually a terrific web site.

  2. Bill,

    I'm not going to give Master a pass on this – since it's messed up to compromise the security of a lock so much – but I wonder how much of this lies on the purchasing agents who interact with Master Lock. Beyond the nickel-and-diming to get the cheapest cost possible on a large order (presumably six-figure quantity of locks, possibly seven-figure), I wonder if whoever does the purchasing is wooed more by "ooh shiny Bumpstop!" than what the implications of Bumpstop in a lock. Here's why I bring this up.

    Every single US-stamped lock since the advent of bumpstop (which seems to be a requirement for low-security locks) that I've seen on Youtube has plain pins in lieu of serrateds / spoorateds. Yet all the old American US locks had these high-security pins. It makes me wonder then if the advent of bumpstop, and Master's fervent promotion of this "feature" (I use this term loosely since it doesn't work), has made the government blind to the fact Bumpstop does nothing – and if anything, makes the lock easier to pick / get into(and possibly opened up doors for PacLock and Commando to bring their own NSN versions in).

    I found this: http://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/DoD_Lock_Program/PDFs/A-A-59486B.pdf about low-security locks,


    http://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/DoD_Lock_Program/PDFs/A-A-59487B.pdf (also low security, some differences)

    to be quite interesting. It makes me wonder how much of the fault is in Master (yes, they've cheapened things), but also how much of it is in the complacency of the government buying from Master on name alone. It also makes me hope PacLock and Commando keep up what they do and push for their serrated pins and proper higher security features to become more prevalent in low-security applications.

  3. Wow. They turned a great core into something so much worse than what's in the ProSeries. Is the government still using this crimped 5 pin monstrosities, or did they reinstate the better cores to the military 5200s?

  4. I just bought a new American A50 padlock 50 series I wanted to add a 6th pin but it's riveted. is there anyway to grab the rivet and unscrew the core or will it spin around?

  5. THANKS!!! i just got one of these thinking they were going to be halfway decent and boy was i supersized when opened it up and saw the pos 5pin crimped core… master would fuck up instant oatmeal if they were in the food business!!!

  6. That's a great lesson Bill. I've seen the videos that talk about the sealed housing–the ML manual has a shaped core follower and instructions for passing the flats that involves a partial rotation. Either way, the idea of filing and reusing is super cool. FYI, the standard difference between 4, 5 and 6 pins is .120 nominal length of the cylinder and lock per increment. The Long leg of the shackle may or may not share the same but then the clearance over the lock may be sacrificed.

  7. @locksmitharmy @bosnianbill Directly from the master lock service manual:
    A good practice when keying a cylinder with BumpStop™ technology is to always dump the Bump Pin. That way when you rekey it you can always put it into a valid location.

    It does not say to leave it out, just remove it so that you place a new one in a valid location because there are certain cuts that cannot have a bumpstop pin.

  8. @thedragonsmith1 Thanks for the info! I have almost 200 of them in stock, I'll experiment with them tomorrow. I sure hope it works, it'll save a LOT of time.

  9. i was being unclear. i sent lsa that lock for r&d. those corea are not sealed close. you turn the plug to a certain position and it becomes freed. ill try to make a vid to show you.
    -Mr. Sour

  10. I should have explained a little more clearly. Sometime last year the American 5200 core was changed from the old one we are all used to (6-pin, removeable, repinnable) to a sealed pot metal 5-pin core. The new core contains all standard pins and one "BumpStop" upper pin and is incredibly easy to rake open or pick. Basically, Master Lock (the new owners) substituted a cheaper, less secure core for the old model – this reduced an excellent lock to a not-so-good lock. Sorry for being unclear.

  11. haha I wonder if they started "dumping the bump" after my bumpstop vids lol… stupid master…

    killer good vid by the way creative correction… your not going to be able to fix the fact that the bumpstop driver chamber is a larger diameter and im sure these cores are made with even worse tolerances due to the crappier metal… but its a start.

    also… adding the circlip only stops accidents once removed… where I ground it the plug will not fall apart if its together

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