CRYPTEX - Portable Combination Safe

Introduction: CRYPTEX - Portable Combination Safe

About: Handmade crafts and products that I make using recycled or waste, cheap and easy to available materials. Also custom products are made using a mix of materials.

The word Cryptex is a neologism coined by the author Dan Brown for his NovelThe Da Vinci Code, denoting a portable vault used to hide secret messages. It is a word formed from Greekκρυπτός kryptós, "hidden, secret" and Latin codex "an apt title for this device" since it uses "the science of cryptology to protect information written on the contained scroll or codex".

The Cryptex featured in the novel The Da Vinci Code is described as a stone cylinder comprising "few doughnut-sized disks had been stacked and affixed to one another within a delicate brass framework", end caps make it impossible to see inside the hollow cylinder. Each of the disks is carved with the entire alphabet and can be rotated independently of the others to create different letter-alignment combinations.

The Cryptex works "much like a bicycle's combination lock" and if one arranges the disks to spell out the correct password, "the tumblers inside align, and the entire cylinder slides apart". In the inner compartment of the Cryptex, secret information can be hidden, written on a scroll of thin papyrus wrapped around a fragile vial of vinegar as a security measure. If one does not know the password but tries to open the Cryptex by force, the vial will break and the vinegar will dissolve the papyrus before it can be read.


In this instructable I will show of making a Handcrafted version of the Cryptex by using easily available materials. This is just a Prototype for showing the making process only, for better security using wood or metal would be more secure enough.

It is very small in size and thus here you can keep or hide any of your important document,private notes, secret formula, or any kind of valuable item, which you do not want to be found by someone so easily. Even though its found it can't be opened without permission or combination.

For its making, I used PVC pipes to make the rings/discs and the inner cylinder. Aluminium rod for making the lock bolts, wood for making the end-caps and Chinese alphabet for a secret password combination so that no one can easily decode it.

So, let's see the making now...

Step 1: Tools & Materials

Below are the few Tools and Materials that I used to make this product, even though you can always use an alternative, if you don't have the one.


  • Mini Hacksaw
  • Scissor
  • Cutter
  • File Set
  • Compass
  • Drill


  • PVC Pipe (different diameter and width)
  • Wooden Bead (used as end-caps)
  • Metal Wire or Rod (used for locking slot)
  • Sandpaper
  • Aluminium Sheet (used to make inner cylinder)
  • Wood glue(fevicol)
  • Superglue
  • PVC Adhesive
  • Some Hard Paper


  • Varnish (used as a finishing coating)
  • Color (silver and gold)
  • Brush
  • Black Marker Pen (used for letter & design marking)

Step 2: Making the Disc - Inner Rings

First of all before diving into the making process I will just say that I have attached a simple and step by step images on every step to guide you through the process.

So, just go through the pictures, you'll understand it quite well.

At first, I took a PVC pipe and cut around 5 pieces of Ring shape and 2 pieces extra as the end-Caps. Then I cut a small portion from each of the Rings, so that it can pass through our locking mechanism.

This will be the inner part of our main Disc Ring.

Note:The width of the gap will be the diameter width of your Locking bolt or the metal rod you will use.

Step 3: Making the Disc - Outer Rings

Next I took another PVC pipe just bigger in diameter than the last one so that, it gets tightly fit in it. In my case I did not get the exact size, so I had to use a spacer between them.

It will act as the outer part of our main Disc Ring. This time I cut the outer ring slightly bigger than the inner one, so that it can rotate freely.

Note:The extra height will be the diameter width of our Lock bolts as before.

Step 4: Fitting Rings to Each Other

As I mentioned in the last step that my pipes doesn't exactly fit into one another, so I used pieces of thick papers in-between the two Rings to join tightly.

You can use PVC glue here or any hard glue of your choice, just it shouldn't come out easily.

Do this with every ring and make ready your Discs.

Step 5: Making End-Caps

This one may be little tricky, here I made both the endings like same as previous Rings. The only difference is, I cut a full gap in the Top end-Cap Ring and a partial cut in the bottom end-Cap Ring.

To cover the end-openings I used a designer wooden bead and cut two circles for each side as end-Covers.

Step 6: Mark Code Gaps in Each Rings

Here, I made a few markings all around the Disc Rings, so that our code remain separated and there will be an alignment for the password.

Step 7: Inner Cylindrical Chamber

Next, we need a Cylinder to fit inside the system and hold our Disc Rings. It should also have a opening, so that our locking system can operate through it.

For this, I used an Aluminium sheet and made a cylindrical shape as above image having a opening gap in it.

Note:again the size of the cylinder gap will be the diameter width of our Lock bolts.

Step 8: Making Secret Chamber

Next, we need to make our secret chamber, where we will hide our credentials. To make this I used a smaller diameter PVC pipe and as well the same end-Disc Rings.

You can clearly see in the above images, how I made and joined the Pipe to the end-Caps. Here also I used some paper spacing for a tight-fitting.

Step 9: Adding Combination Locking Bolts

Then, is the part for adding some strong vertical bars to chamber, so that it doesn't get easily broken. For this I drilled the desired number of holes to the cylinder, at even spaces where the the Disc Rings will get fitted.

Next, I used 2mmAluminium rods for the bolt mechanism. I cut them according to my size and tightly fixed them in the holes with strong adhesive.

Step 10: Fixing End-Caps

Now, our both the cylinder tubes are ready.

Then I added two circle wooden pieces that I already kept ready to both the opening sides as a cover and fixed them with strong adhesive.

Step 11: Coloring and Finishing

Here is the part for coloring and finishing. I used Golden color to the outer Discs & end-Covers and Silver color to the remaining spaces.

Also I used some finishing coating all over the surfaces, to have a glossy finish.

Step 12: Marking Designs and Secret Coding

Here is the last part, the design. For this I used a Black Marker pen to decorate all around the top and bottomend-Caps.

For the combination part, I decided to add some different coding or a different type of password so that it becomes very hard to understand or even gets very much complicated to decode.

That's why I gone with the Chinesealphabet coding. So, I marked my secret code word in the locking alignment and some other letters by shuffling for making confusion.

It is really complicated to solve and as well very much beautiful to look at.

Step 13: Assembling All Parts

Now, all our parts are finished and ready to assemble. Insert all the Disc Rings one by one but set loose, and only fix the last Disc Ring to the Aluminium cylinder using some strong adhesive.

And finally insert the secret chamber onto it and shuffle the combinations.

Step 14: Finished Product

So, everyone!

This is our finally finished product. After completion it looks very beautiful with these silver and golden coloration. This is very portable and suitable to fit in Pockets, so that one can easily carry it anywhere. Also you can set any password combination of your desired length, just you have to vary disc numbers & length.

Also, it is not an exact replica, but however it can be used for safekeeping your private properties or storing any confidential document as well.


Therefore, Thank You Everyone!

Hope, you all have liked this Instructable and learnt something as well.

If so, Please Follow us, also SUBSCRIBE to our YouTube channel TechnoCraft STUDIO for more amazing contents like this.




Step 15: References

Hide It Challenge

Grand Prize in the
Hide It Challenge

1 Person Made This Project!


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    Jewelry Challenge
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    Photography Challenge
  • Raspberry Pi Contest

    Raspberry Pi Contest


AMbros Custom
AMbros Custom

5 weeks ago

A big congratualtion and well done man. you deserve..


Reply 5 weeks ago

I really appreciate that you took the time to express your feelings.
It's a big honour for me.
Thank you so much sire !


6 weeks ago

This is wonderful!!!! Makes me want to re-read The DaVinci Code!!!


Reply 6 weeks ago

Wow ! Thanks a lot.
Its great to hear that it inspire you to re-read Da Vinci.
I only watched the movie, never read the novel, How is it?


Reply 5 weeks ago

The novel is better (of course)!


6 weeks ago

Nice job ☺


Reply 6 weeks ago

Thank you so much.
Did you like it?


Reply 6 weeks ago

Of course


Reply 5 weeks ago

It's my pleasure to hear that.