The Master Lock 1590D isn’t an overwhelmingly common escape room lock. (That’s probably a good thing for reasons that I discuss below). That said, it is a strange and interesting device that does show up from time to time.
Since it is commercially available and does show up, I decided to run an analysis against it. In doing so, I learned some nifty things.
Unlike the previous letter locks that we’ve analyzed, the Master Lock 1590D does not have multiple disks with individual letter distributions. Instead, the 1590D functions like a traditional locker lock. All of its letters are available at once.
The distribution is:
A D E H J L N R S T and the numbers 0 through 10.
There is one interesting thing to note about this lock before reviewing the word permutations.
Letters may be repeated:
There was nothing in the lock’s documentation, nor did I find anything online… but when I attempted to input repeat letters into the lock, it accepted them. “AAA” was a valid combination.
This was a relief because I was pretty certain that I was going to break the lock when I tried it.
There was one significant differences from the first analysis:
I asked Rich to run the analysis twice, once using only the actual letters, and a second time substituting letters that look like numbers. These tabs are running across the bottom of the spreadsheet.
1. The fact that the 1590D accepts repeated letters really surprised me. This greatly opened up opportunities for making words.
2. Word options at 3 letters are minimal. This isn’t really a surprise.
3. The addition of a few extra numbers as letter substitutions expanded the word pool dramatically.
4. If you look in the right two columns, you’ll find a ton of 3-letter abbreviations. Government agencies (DOJ), stock symbols (JNJ), nicknames (J Lo), and fictional organizations (JLA) seemed interesting and potentially useful. The right most column is far more useful for this lock than for some of the larger locks that we’ve previously analyzed.
5. Master Lock’s commitment to including the letter “J” in their word locks continues to bewilder me as it is not useful for making words. The only reason that I can think of is for making people’s initials, as “J” is a common first letter in names.
I have found that players are generally confused about how to operate this lock.
In my opinion, locker-style locks are a less-than-stellar option for escape rooms. I think they should be avoided most of the time. The same goes for the 1590D.
My opinions notwithstanding, I know that this lock will get used in escape rooms and in classroom games, so I offer this analysis.
Dimensions: Body, 1.75 inch (4.5cm) wide 1.5 inch (4 cm), shackle height 1.5 inch (3.9cm), shackle width 0.25 inch (0.6 cm)
Price: $10-25 (depending on the color)
Manufacturer: Master Lock
What the Master Lock 410 lacks in durability it makes up for in aesthetics… at least for escape room design purposes.
For the right escape room theme, this is a clever lock to use in place of “do not touch” stickers. It could also work well just as an eye-catching lock.
From a user standpoint, this is a keyed padlock. There is nothing unique about its operation.
From a construction standpoint, the Master Lock 410 is an utterly bizarre lock. Its body is made of plastic and its shackle is not hardened… but it has the most pick-resistant core that Master Lock produces.
The Lockpicking Lawyer did a humorous analysis of the paradox that is the Master Lock 410:
Use in Escape Rooms
There are two clear uses for the Master Lock 410 within escape rooms.
Do Not Touch Indicator
The Master Lock 410’s aesthetic makes it jump out as a natural “do not touch” indicator.
Its unique look and feel – compared to other locks – makes it obvious and memorable.
Additionally, the plastic body means that while its durability may be questionable, it is unlikely to damage anything on your set if it swings against props.
Depending upon the game environment, the Master Lock 410 could look like a natural part of the set while still standing out. The same cannot be said for most “do not touch” stickers.
The Master Lock 410’s interesting aesthetic means that it could play a unique role as an active padlock within an escape room.
My big concern for this padlock as an active prop is durability.
The unusual Master Lock 410 is a Lockout/ Tagout lock (LOTO).
Lockout/ Tagout is an industrial safety precaution whereby all of the workers involved with a dangerous piece of machinery place a lock on the device that prevents it from working until all of them remove their locks.
This ensures that no one is stuck in a dangerous position when the machinery is activated. These locks come in multiple colors and have labels so that individual workers can identify their own locks.
Incidentally, the Master Lock Hasp that occasionally shows up in escape rooms is a different LOTO device… but that contraption is a story for another day.
➕ Master Lock 410’s plastic body means that this lock will not damage anything that it is hanging on or near.
➕ The soft shackle of the Master Lock 410 means that an escape room operator could easily cut this lock open with bolt cutters in an emergency.
➕ The unique aesthetic of the Master Lock 410 could make this lock look at home in certain escape room environments.
➕ There are many color options for the Master Lock 410 including red, black, green, orange, purple, yellow, and blue. Prices may vary for different colors.
➖ The plastic body calls the durability of this padlock into question. Its body is far more likely to suffer serious damage than most other padlocks.
➖ From a security standpoint, the Master Lock 410 is utterly insufficient as it has no hardening to physical attack. This is a product that makes more sense in an escape room than in most real life situations.
➕ The shockingly robust core of the Master Lock 410 makes it an ideal practice lock for pickers. It’s a really tough pick compared to just about everything else that Master Lock sells.
Tips For Using
You may want to apply some lacquer or resin on top of the sticker to prevent it from peeling off.
Buy your copy of Master Lock’s 410, and tell them that the Room Escape Artist sent you.
I recently published an analysis on the Master Lock 4 letter combination locks. They have an unusual letter distribution and I was curious how many English words could be generated with those locks. It turned out that those Master Locks could create a lot more words than I had anticipated.
Absolutely everything about this analysis and its outputs conforms to the same information presented in the last letter lock analysis, so I won’t rehash it. It’s on the Master Lock post if you’re interested.
Odd Letter Distribution Hypothesis
After publishing the last analysis some members of the room escape community proposed a hypothesis about the odd letter distribution on those Master Locks:
It seemed like Master Lock may have been trying to make it impossible to spell curse words.
This seems like a valid answer for both Master Lock and WordLock’s letter selection. I cannot prove this one way or another, but you cannot generate the most popular American English swear words with these locks… so that’s probably not a coincidence.
Nevertheless, sifting through the wordlist revealed a few “vulgar” or degrading words… and I’m including them because my inner 10 year-old thinks this list is hilarious:
There is no way to generate a single answer to the question “how many English words can this lock create?” English is a constantly evolving language. Words are created, usage shifts, and words fall into disuse.
Column A is the common English word list. This is by far the most useful column. It has 695 words.
Column B is the “ENABLE” word list. These are still words, but they are obscure or old English.
The next three columns are decreasing useful, with the fifth column being words from Wikipedia (which includes acronyms, initialisms and the like).
Each list omits the words found in the previous lists.
I’ve included all of the columns in the spreadsheet because even the less useful columns have some interesting entries… They are just few and far between.
Bragg used TEA Crossword Helper, which is anagramming software on steroids. This is the kind of software that you use if you’re really serious about winning a major puzzle hunt.
From the TEA website:
“TEA comes with a database of over 6 million words and phrases including the title index for the English version of Wikipedia. These answers are classified by their familiarity, so you always see the most likely ones first. You can look up the meanings in the integrated dictionary/thesaurus or on the Internet. TEA is faster and more convenient than word lists in book form such as crossword completers, crossword dictionaries and crossword keys.”
Is There A Better Distribution?
The letters on each disk are pretty curious, especially when you notice oddities like the “J” in the first disk or the “Y” in the second disk.
From a letter frequency standpoint, these are not great letters to drop in those positions.
I reached out to Master Lock to ask how they chose this letter distribution, but they could not be reached for comment.
I suspect that there are more effective letter distributions possible that would generate even more words, but after a quick attempt at doing better, I fell a bit short. If you find one, I’d be curious to see it.
However, whether or not there is a better distribution, this is the one we have on these locks. It’s a lot of options. Feel free to use this list as a tool.
This hard plastic spring-loaded sheath slips over the mouth and neck of a bottle. It seals shut using strong spring tension and locks shut with a key.
I was shocked at the breath of bottle necks that the Tantalus Wine and Liquor Bottle Lock fit over, both narrow and wide.
Securing a wide-mouthed bottle of whiskey.
Securing a narrow-mouthed bottle of beer.
There are two downsides to this lock:
Aesthetically, it’s unattractive.
Given its plastic construction and the surprisingly strong spring tension, I suspect that it might give out with repeated use. That being said, I’ve opened and closed it a few hundred times and it’s still working like the day I removed it from the package. At $15, it’s also pretty disposable.
This is another hard plastic spring-loaded sheath that slips over the mouth of a bottle… except this one is junk.
Due to its narrow diameter and exceedingly inflexible design, this lock cannot fit around most of the bottles that I attempted to secure.
It couldn’t come close to securing the largest bottle we owned.
This bottle wasn’t massive, but the lock could not close.
It fit over this beer bottle, but it also pulled off with no resistance.
When it does fit, it looks aesthetically pleasing.
It opens with a customizable 3-digit numeric combination. With the correct digits in place, it snaps opens with the push of the silver button on the top of the lock. Its operation is self-explanatory.
It feels so flimsy that I continually worried that I might have broken it while trying to put it onto a few bottles. I didn’t break it, but I wouldn’t bother with it for an escape room because it almost certainly won’t be durable enough, even at $9 per lock.
This metal 4 digit numeric combination lock looks good and feels great. On initial inspection, it seemed like a real winner. Then I saw how it worked:
This lock completely replaces a bottle’s existing top/ cork/ stopper.
With the correct code in place, it inserts into the mouth of a bottle like a cork or stopper. Then you start twisting the top of the lock. In doing so, it slowly expands the stopper until it fills the mouth of the bottle and cannot be removed without unwinding it.
It takes a lot of spinning to expand or contract it. This would be baffling in an escape room.
It also didn’t fit most of the bottle mouths that I attempted to close with it. The bottle mouthes were too wide and the stopper ended up distorting in shape.
Normal, retracted state.
Expanded, closed, and distorted state.
This lock is clunky, weird, and decidedly user-unfriendly. Absolutely skip this thing.
A word on security
Escape rooms aside…
While locks like these could function as a deterrent to thieves lacking motivation, none of them would adequately secure liquor from a motivated thief. All of them are breakable with enough force or some basic tools.
The 3 digit lock only has 1,000 possible combinations; that wouldn’t take all that long to test.
The 4 digit lock has 10,000 possibilities, but it has some pickable weaknesses.
Tantalus Wine and Liquor Bottle Lock is pickable, but due to its heavy spring tension, it was pretty difficult to pick. It is my choice for both escape room gameplay and bottle security.
(If you purchase via our Amazon links, you will help support Room Escape Artist as we will receive a very small percentage of the sale).
Price: $24.75 (prices may vary based on seller and configuration)
Why test this lock?
tl;dr (too long; didn’t read):Escape rooms are a difficult environment for locks, and the Marine Brass 38 was designed for harsh environments.
Padlocks aren’t typically designed to be opened a dozen times a day. They tend to age quickly and seize up from the overuse of an escape room.
The Marine Brass 38 was designed specifically for use on boats and docks, a different harsh environment. Between the moisture and salt, locks don’t usually fare well near water. This is why I decided to grab one to test for escape room usage.
tl;dr:The Marine Brass 38 has a simple, lightly branded, largely timeless look.
The Marine Brass 38 is built from thin interlocking pieces of laminated brass. Its body is dense and solid. Its shackle is a boron steel alloy. The lock has barely any branding on it.
It has a simple, clean, and classic look. Out of the box, it is bright and shiny, but it will quickly darken with handling.
The brass aesthetic makes it easily visible in a room. It doesn’t suffer from the in-your-face branding that makes many of the more common locks feel out of place in historical rooms. It doesn’t look ancient, but it doesn’t look overtly modern either.
The brass keys look like they belong with the lock.
tl;dr:The Marine Brass 38 works smoothly. It is less likely to break than most of your common escape room locks.
The lock’s dead core means that the cylinder holds no spring tension. Similarly, the shackle and locking mechanism have no spring tension. As a result, the key takes nearly no pressure to turn. Once unlocked, the lock simply falls open. Everything is smooth.
This lack of tension reduces the amount of kinetic energy being transferred between the various lock components. Additionally, with fewer moving parts in the lock, there is less that can go wrong.
You can skip this section if you’re only interested in escape room usage.
The Marine Brass 38 is a 5-pin lock. All of the pins are security pins (alternating serrated / spool pins). The keyway is narrow and paracentric (curved) like a European keyway. I can pick and rake it open (because the lock I have has fairly level pinning), but it certainly takes a lot more effort than any other lock I have found in the price range.
The shackle is held shut with ball bearings that prevent shimming.
The back of the keyway is shielded. I could not find any methods of bypassing, nor did I find anyone publishing information about possible bypasses.
Knowing that Master Lock No.1 – 4 can take a bullet, I have no doubt that this similarly designed Commando Lock can as well.
Lock Dimensions: 3 x 1.625 x 0.875 (inches)
Shackle Diameter: 0.5 (inches)
Shackle Height: 1.5 (inches)
Key Dimensions: 1.75 x 0.875 (inches)
Should I buy Commando Lock’s Marine Brass 38?
Manufacturing in Michigan, Commando Lock Company does a mindbogglingly good job of producing a high-quality, low-cost product. I keep hearing that it can’t be done in America, but damn it, they did it.
I’ve picked and opened this Marine Brass 38 somewhere in the realm of 500 times and it still opens like the day I pulled it from the box. This is not the case with the Master Locks that I own, which stick and seize up with regular use.
I feel confident recommending this lock for escape rooms because it truly feels up to the task.
We met the creator of these contraptions, Justin Nevins, at the Chicago Room Escape Conference back in August. His product was the darling of the tradeshow floor and he sold out before we could get our hands on one.
So we arranged to meet with Nevins in Seattle while we were visiting for PAX West.
There were three questions that we needed to answer about his device:
Could it stand the punishment of regular use in a room escape?
Could I pick it open?
Could his cryptex justify its $300 price point?
The problem with every cryptex tube that we had seen in a room escape was that it was easy to break and even easier to pick. Could Nevins’ cryptex be that much better?
Spoiler alert: Yes
Before we get into the intricacies of the cryptex tubes that are available, let’s cover a little history.
What’s a cryptex?
A cryptex is a tube with a combination letter lock built in as a self-locking mechanism.
Each of disks has all 26 letters of the alphabet etched into them. Any permutation of letters is possible. With 5 disks, this is 11,881,376 possibilities.
Where did the idea come from?
The concept came from Dan Brown in the novel turned movie, The Da Vinci Code.
Brown created a compelling fiction where it felt like the cryptex had been around for centuries, but it didn’t actually exist… yet.
Who created the cryptex?
Although Brown came up with the concept, the aforementioned craftsman Justin Nevins created the first cryptex. While driving across the country listening to TheDa Vinci Code on audiobook, the concept of the cryptex captured his imagination and he began conceiving ways to build one.
After a series of prototypes, in 2004 Nevins eventually created a durable cryptex that was fit for sale.
I wish I could have Hans Zimmer scoring my pensive puzzling.
The most common cryptex found in room escapes, this thing works pretty well out of the box, but eventually the innards buckle and it becomes flimsy and pickable.
At ~4 inches in length, this little guy has almost no capacity. Designers are usually stuck hiding small keys, bits of paper, or maybe a battery inside. It is limiting.
It also suffers from the same input problems as the piggy bank. Shifting one letter generally changes its neighbors. This really diminishes the psychological satisfaction of inputting a digit that you think is correct.
This is the official licensed Da Vinci Code cryptex (licensed by both the movie rights holder and Nevins).
It looks like the cryptex from the movie and generally feels better to operate than the previously mentioned tubes. It also comes in an attractive wooden box that is nowhere near rugged enough to survive life in a room escape.
But once again, this thing is subject to breakage after repeated use and it is pickable. Here’s a demonstration:
Variations on this picking method work on most of the other cryptexes.
The other big catch with this model is that it’s expensive. At nearly $200, you’re 2/3 of the way to Nevin’s $300 price point.
“Replica Line” is unfortunate branding for Nevins’ low-end Cryptex. It is a replica of his more elaborate products, but it’s an incredible, well-constructed, and aesthetically pleasing device.
Nevins gave us a Cryptex to review with a puzzle and a wager. If we could solve the puzzle and thus open it before we left Seattle, it was ours to keep. We had to solve it before flying home because this thing looks like a pipebomb when viewed through an x-ray machine.
His puzzle was devious and didn’t generate a word. Instead we ultimately derived five random letters and had to solve a different puzzle to sort their order.
This was a great test because it took us a few hours to solve the puzzle. When we hit a puzzling wall, we switched to brute-force and picking.
I tried every trick I knew to feel my way to an open, but the Cryptex gave away nothing. All picking attempts failed. Fortunately we eventually puzzled our way in. So consider this your disclosure that we received a free Cryptex from Nevins.
Since returning home, I spent hours trying to break into the Cryptex through picking and I absolutely cannot do it. I am reasonably certain that it’s possible to write some software to crack it, but that would be a massive undertaking and it would probably still take a lot of time to open it with a software assist.
How it works
From a room escape player standpoint, it works just like the others, only smoother. Input the correct combination, give the inner tube a little pull, and take your prize.
From a designer standpoint it’s easy to setup. The inner tube is static; the outer tube is where the magic happens.
The outer tube is made of 4 different types of components:
The frame (1) is the aluminum and brass structure that holds everything.
The disks (5) have brass outer rings with the alphabet on them and polycarbonate slotted inner rings with false slots (to torment pickers).
The spacers (5) are marble-patterned polycarbonate pieces that space the rings.(These spacers come in 6 different colors.)
The endcap (1) is an aluminum and polycarbonate piece that looks like a spacer, but has a locking mechanism to hold the outer tube together.
It is possible to special order a larger Cryptex with more disks.
If you want to change the combination, you take it all apart, pop the inner rings from the outer rings, and set it as needed.
To make sure that players can’t reset the box in game, Nevins has developed a technique to freeze the rings and make them virtually inseparable. Ironically, the technique actually involves putting the rings into a freezer.
It’s hefty, weighing 2 lb 12.7oz / 1.266 kg.
The outer tube measures:
length 8.3 in / 21.082 cm
diameter 2.375 in / 6.0325 cm
The inner tube measures:
length 7.95 in / 20.193 cm
diameter 1.62 in / 4.1148
It’s a much bigger cryptex than the others (except for the piggy bank).
It also comes in 6 different colors:
Why this is a superior cryptex
There are a number of factors that make Nevins’ cryptex a vastly superior device to the other tubes we’ve discussed.
It’s far more durable. It is made of solid materials that don’t have the opportunity to compact. As a result of this construction, it’s far less pickable. It’s possible that someone more skilled than I am could pick their way in, so I won’t say that it is unpickable.
The cryptex’s capacity increases options for what is hidden within it. This opens up additional design opportunities that the smaller tubes do not.
The color options are more varied and increase the odds that the cryptex will look like it belongs in the room. The Da Vinci Code-looking cryptexes almost never look like they belong in a space.
Lastly, Nevins stands behind his products and welcomes customers to contact him with any issues. He hasn’t needed to create a formal warranty program, but he will work with his customers to make things right should they go wrong.
$325 is a steal when you consider the constant replacement needed to keep the other cryptexes in working condition.
“But I want something even cooler”
If you want something fancier and money is no object, then Nevins offers more elaborate models.
The Nevins Line costs $1,000 – $2,500. It offers the same functionality as the replica, but with beautiful wood or stone materials.
For high rollers, the DaVinci Line runs upwards of $3,000 for some intense custom work and fancy materials. At this price point Nevins will create nested cryptexes… which I imagine are really cool.