Assassin's Creed Hidden Blade - Functional Prop!!

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In this Instructable I will be teaching you how to build a working replica of the Hidden Blade from the Assassin's Creed video game series. Don't be intimidated by the number of steps involved, this is a fun project that should only take you a few days in your workshop and should only cost you around 30 or 40 dollars. 

My Design Goals for this Project:
  • I wanted the Hidden Blade to be functional, (to either extend or retract by moving my hand or wrist).
  • I wanted it to look as nice as possible and as real as possible.
  • I wanted it to be easy to build.
  • I didn't want it to require a lot of special parts or tools.

The process of making the Hidden Blade can be broken down into two main parts:
  • Building the blade mechanism (Steps 2-6)
  • Making the Leather Bracer (Steps 7-13)


Hidden Blade Mechanism Materials List:
  • 16” Drawer Slide – This will be what holds the blade and allows it to extend and retract.  You can purchase this from home improvement stores like Lowes or Home Depot for about $6. It is important that you get exact same one that I used otherwise the measurements won't work out properly. examine the included picture for product details.
  • Replica Blade – I used a replica WWII dagger for this. the measurements of the blade are 10.5"long, 3/4" in width at the widest point, and 1/8" in thickness. These measurements, especially the 1/8" thickness, are important because there is not a lot of clearance between the moving parts of the hidden blade so be prepared to do some file work to make things fit. To get the blade, dismantle the dagger and discard the handle, pommel, and cross guard components. The blade I used came very dull with smooth rounded edges, if yours is sharp or pointy I highly advise that you sand away the edges so that they are nice and dull, this will make it safer to use and may keep you out of trouble. Cost $12, purchased at local flea market.
  • Small Coil Spring – This spring will be what retracts the blade when it is extended.  It needs to have very light pull strength and should be 3 to 4 inches in length and approximately 1/4" in diameter.  I purchased mine from Lowes home improvement store as part of a variety pack of springs for around 3 dollars.
  • Flat Spring – This will hold the blade in place when it is extended.  you can make this component out of an hacksaw blade, simply cut off a three inch piece of the blade and grind away the teeth.
  • Assorted small nuts, bolts, and washers – The size of the nuts, bolts, and washers doesn't really matter, anything around 1/8” will do fine.  You’ll just have to drill your holes based on the size of bolts you are using.
  • Small Nails – These will be cut and turned into rivets to attch the blade lock in step 5.
  • Rubber Washer – when the blade retracts it retracts with a lot of force, this will be used to dampen that force i.e. shock absorber. you can purchase rubber washers in various shapes and sizes at hardware stores, you do not need to have the exact one pictured, just something similar.

Leather Bracer Materials List:
  • 2 square feet of 5 or 6 oz. leather – This can be purchased at leather suppliers such as Tandy Leather, however you can also use leather from an old suitcase or coat to cut down on cost.
  • Leather Dye – For coloring and finishing your leather, if you use repurposed leather from an old suitcase or coat you won’t need this.
  • Button Snaps – These can be purchased from retailers such as Tandy Leather or Michaels Crafts.
  • Rapid Rivets – These are used to attach the blade mechanism to the bracer. They can be purchased from Tandy Leather or Michaels Crafts.
  • Ring – Pick something that fits either your middle or ring finger.
  • String/Cord – Pick something strong but light, kite string or the inner strands of paracord work very well.  You’ll need about 1 foot of this.

  • Dremel Tool and Metal Cutting Disks – You will use these for cutting and modifying the draw slide parts. If you don't have access to a Dremel, you can also use a metal hacksaw for the cuts.
  • Files and Sand paper – For removing sharp edges left by Dremel cutting disks.
  • Drill and Drill Bits – You can use a hand held drill or a drill press, both work well.
  • Wire Cutters – For cutting your spring to adjust its strength.
  • Screw Drivers – Installing screws.
  • Metal Center Punch - For marking where you are going to drill holes on the drawer slide and blade.
  • Hammer – for peening down rivets.
  • Xacto Knife/Utility Knife – For cutting your Leather.
  • Paper or Poster Board – For creating patterns for your bracer.
  • Leather Working Tool (Beveler) - This tool is used to create the Assassin's Creed symbol and designs on the leather bracer. The one I used is known as a B60 Craftool Beveler Stamp and is available from Tandy Leather for around 8 dollars. 
  • Awl/Drill/Leather Hole Punch – Some way of putting holes in leather.
  • Ruler – Creating patterns.
  • Pencil – Marking patterns on leather.
  • Permanent Marker - For making patterns and cut lines.
  • Safety Glasses - Always wear eye protection when drilling and cutting the metal parts of this project.

Disclaimer:  Please use common sense when making and wearing this prop.  If you have any concerns about the blade material feel free to replace the steel blade with a wooden or acrylic analog.  If you're planning to tackle this project then you most likely already have all the skills necessary to make whatever changes you deem necessary to make this prop suitable for your specific situation and needs. Be safe and be smart!
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ethomas157 days ago
Where could I find a plastic blade to fit this
ewells49 days ago
Love the build! A have one question though. Would I be able to make two of them for an ezio cosplay? Or would I have to change any steps?
Matt2 Silver (author)  ewells49 days ago
That's a great question ewells4,
I designed the hidden blade so that it could be worn on either the left or right arm so you wouldn't need to change anything if you wanted to make a set for Ezio Cosplay, simply make two and you're good to go.
Thank you since all the other tutorials have had to change the string position it's great to find one thst I just have to copy each step again :) and again great build i will post pictures of my
Probably just the amount of leather button snaps ect.
ethomas1510 days ago
Well I've been thinking and a thought came to me what if u took another piece of leather and put it over the blade mechanism so your arm would be on the leather not the mechanism
ethomas1510 days ago
Couldn't u place the hidden blade mechanism inside the bracer instead of the out side so it would really be hidden if so how much room would u have to add to the bracer
Matt2 Silver (author)  ethomas1510 days ago
You could potentially conceal the blade mechanism within the bracer however you would have to consider the spring assembly on top of the blade mechanism, my thought is that this would get hung if the blade were installed inside the bracer. perhaps you could create some sort of blade mechanism cover to correct this issue, as for the dimensions of the adjusted bracer, I'm afraid that I wouldn't have a clue, it would be trial and error until you found the proper fit for your arm.
Ok thanks?
gappleby113 days ago
Ok great thanks! And yes I am switching the blade to plastic I will post a picture when it is finished thanks for the help.
gappleby119 days ago
Hello, I was wondering would the dimensions fit a 14 and a half yr old boy? See I've got all the games so I'm a big fan and I'm hoping that with this prop I'll be able to wear it to comicon?
Matt2 Silver (author)  gappleby117 days ago
Hello gappleby1,
Sorry it took me a while to get back to you. These dimensions should fit your arm, the blade mechanism might be a bit long but the way the hidden blades fits your arm means that any additional length shouldn't really matter. The only other thing I would consider is switching the blade material. In this instructable I use a steel blade but you can't bring metal bladed props to comicon, so switch out the blade for something like plastic or acrylic. Hope this helps and good luck, I'd love to see your finished project so please consider posting a picture when you're done!
Hi, i was wondering if i could buy one. I will pay any price. This is amazing
keari01 month ago

Can a real blade and not a replica be used with this? just curious. not like i would use it for actual assassination but can it be done?

Matt2 Silver (author)  keari028 days ago

Hello Keari0,

Sorry for the small delay in answering your question, You could absolutely replace the replica with an actual working blade. The only difficultly I can foresee would be in drilling the attachment holes. Where the replica blade I worked with was made of softer steel, a real blade would be made of a much harder alloy meaning that you would have to work much harder to drill those holes through.

Also, I would advise taping off the edges of the blade to protect your hands and make sure that you don't try to hold the blade with your hands while drilling, instead use a clamp as stated in the instructable.

Lastly remember to be careful and responsible with whatever you end up creating, Happy making!

You should sell it to the whole world wide Assassin's Creed fans, i would definitly buy it.
Matt2 Silver (author)  Edvard Seära28 days ago

Thanks Edvard, that is a nice compliment! Make your to check your Private Message Box, I messaged you in regards to your question about downloading this instructable as a PDF.

Kain...!1 month ago

The best cheap Hidden Blade that i ever seen ! good work man !

Kain...!1 month ago

The best cheap Hidden Blade that i ever seen ! good work man !

jhersey1 month ago
hey I just wanted to ask. could I swap the blade for a pvc pipe cut to the proper dimension's? if so, what are the exact measurements I would need to follow?
boa snakes1 month ago
great craftsmanship! Just a idea for your instructable can you please use the exact item's that you used to make your hidden blade, thanks
salmons1 month ago
where can i get the blade please
temery1 month ago
And where exactly would one get a replica WWII dagger? I'm guessing eBay or something like that, but I could be wrong.
Matt2 Silver (author)  temery1 month ago
Hello temery,
there's a variety of places you can look to find a dagger for this project. online retailers like, or even Ebay all carry a wide selection of replica weaponry.
Mr DIY1 month ago

can i cut out a blade from a sheet of metal

Matt2 Silver (author)  Mr DIY1 month ago
Absolutely. just remeber to stick to the dimensions of 1/8 of an inch thick, 3/4 of an inch wide, and roughly 10 inches long. Best of luck!

thx. by the way amazing blade

Great instructable. I have one small problem though, could you possibly give me the dimensions of the spring you used? It says that you need a relatively weak one, but exact measurements would be nice. Great leather working skills by the way!

Matt2 Silver (author)  thefaceofboe1 month ago

Hello the faceofboe (fantastic name by the way, love the Doctor Who reference.)

Sorry it took me a few days to get back to you. Unfortunately it is hard for me to give exact specs on the spring as what spring you will need will depend on a variety of factors. I can offer one little tip though, while working on my first hidden blade I used the spring from an old desk top stapler and that seemed to work very well. I cut it to roughly 3 inches in length if I remember correctly but I would advise you to start long and trim the spring as need so that you dial in on the perfect tension.

Thanks for your kind words about my leather working skills!

Best Regards!

Very good looking! I've read all of the comments section. Yes, its a bummer that there isn't much length of the knife that comes out, but this is a prop so who cares. Just my opinion. Personally, I like the instructions about the leather and how to measure and make the fore arm cuff! I think I may just make the cuff! Peace

mtjiputra3 months ago
And by the way, maybe you can add another lock at the near of the tip of the blade. just for a little safety precautions if the blade accidently slide out
mtjiputra3 months ago
Thanks a lot man. This instructable is perfect! Keep up the great work
mtjiputra3 months ago
Dear matt, can you please specify the blade's weight because the material of blades are sometimes different. so even the dimensions are the same,the weight can be different and it can be a problem when the blade retracts. if there is the specs inside this instructables i'm sorry for bothering you (bad eyesights)
Matt2 Silver (author)  mtjiputra3 months ago

Hello mtjiputra,

Good question, I would estimate the weight of the blade to be around 3 to 4 ounces. You make a good point that the weight will play a role in the inertia needed to "flick" the blade into the extended position. If you decide to use a wooden or aryclic blade in place of the steel one you may be able to off set the weight difference by adding weight onto the inside slide that the blade mounts to. You could also toy around with different spring lengths and strengths to find one that would be better suited to the lighter weight of the wood or acyrlic blade potentially even swapping our the metal coil spring for something like a rubber band that will require far less force to stretch and retract. I hope this helps, best of luck!

skemp63 months ago
I think im going to make a wooden blade instead if my short blade for saftey purposes
skemp63 months ago
I cant find a.blade.that is that lond do you.think I could manage.with
Matt2 Silver (author)  skemp63 months ago

Hello skemp6,

you could certainly make do with a shorter blade the only problem would be that the blade would not stick out as far once it is extended.

nikolojedison3 months ago

Question: What are the dimensions of your blade? I'm planning on making this but w/ a wood or plastic blade. Other than that, sweet build!

Matt2 Silver (author)  nikolojedison3 months ago

Hello nikolojedison.

The blade dimensions are:

10.5 inches in length

3/4 of an inch in width at the widest part of the blade

1/8 of an inch in thickness

The 1/8" thickness is very important as there isn't a lot of clearance between the moving parts of the drawer slide. Good luck on your build please post pictures as I would enjoy seeing your finished project.


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