Yak-Proof Survival Knife




About: I made a beer mug with only a knife and a hatchet. I think that says a lot about me.
Y.U.R.T. - Yellow Ugly Rescue Tool ;-)

I wanted to call this Instructable "Make a heavy duty survival knife from an rusty file for less then 15 dollar in less then 2 hours with only basic tools", but sometimes less is simply more...

Survival. Again. I'm doing this - this what? this sport? this spirit? this way of life? I like the last one! - for many years and every survivalist comes to The Moment of asking the only question that counts:'which knife???'
On the net you'll find thousands of 'survival knives' and a few brands offer really good stuff.
Instead of buying one, as a survivalist I prefered making one.

Making your own survival knife is going back to basics of survival: be inventive or die, or so.

Untill now I always used a customized tactical knife (my custom Muela Tornado 'Black Betty' - see picture). No need to spend an Instructable on this: take the knife, take a grinder, take a sander and you're done!

A few months ago I decided to make a survival knife from a file with only some basic tools. That evening project resulted in Y.U.R.T, I agree, the most ugly knife you've ever seen. But one that does the job!
YURT exceeded my best expectations. It's 200% yak-proof and a lot more reliable than a lot of the so-called 'survival' stuff you'll find on the net - with all my respect for those brands that matter.

Why a file? Because it's very hard steel, easy to find, and cheap.

All you need:
  • a big grandpa's file
  • a big hammer handle
  • chemical anchor
  • angle grinder
  • sander
  • drill
  • safety gear
Dimensions of Y.U.R.T.
  • weight: 272 gram - almost 10 oz
  • overall length: 26.5 cm - a bit more than 10 inches
  • blade length: 11.5 cm - 4.5 inches
  • blade width: 3.5 cm - 1.4 inch
  • maximal blade thickness: 0.7 cm - 0.27 inch

Step 1: Preparing the Blade

First of all you've got to find an old file. I found mine in a scrap yard and had it for 1 euro. Design rawly the blade you want to cut and start grinding.

  • the tang aka 'root' has the same length as the blade!
  • cut some grooves in the root so that the anchor will have more grip
Once you cut the blade out of the file it's shaping time. Use angle grinder and sander and be careful not tu 'burn' the steel (when it becomes blue). Anyway, it's a survival knife so I didn't spend lots of time on design. Not this time.

For me, a survival knife needs four major functions:
  • digging
  • cutting
  • splitting
  • bushcraft
Therefor, I chose to give it a specific design:
  • pointed for digging and carving
  • an axe-styled upperpart for splitting
  • a hollow shaped underpart for bushcraft and potato peeling
This 'beaver-tail' shape leaves a lot of weight towards the tip of the knife - great for basic clearing work.

Use sander to finalize.

Step 2: Preparing the Handle

For less than 5 euro I bought this hammer handle 'elasto fibre'.
Why not wood? Because I wanted it to be water-resistant and I didn't give a spanish beer about beauty.

Cut the handle into the size you want (make it longer than usual) and keep the big end.

Drill a hole in the small end (same diameter of the blade 'root').

Ready it is!

Step 3: Assembly!

Prepare the chemical anchor (5 euro). Be careful to evacuate all the dust out of the hole you made.

Chemical anchor? This sticky stuff is used a lot in building construction. We use it to anchor iron poles into concrete, to anchor stairs and balcony's and everything that has to be as solid as possible. With this stuff you'll putting almost everything together. It's incredibly solid, and dries extremely fast.

Unorthodox way of knife-making? It is!!!

Fill the handle with the paste and put the blade in place.

Clean the excess, and let it solidify for a couple of minutes.

End with a sharpening session and ready is your survival knife!!!

Step 4: The Big Test

To test YURT's valor I did some rude tests:

- I cutted down some arm-thick logs of hard wood (cooked by bushfire)
- I splitted them into Belgian fries
- I digged some holes in a rocky soil

    • The knife behaves extremely well!
    • The heavy weight at the end makes cutting an easy job!
    • It should have been a little bit longer for splitting stuff, nevertheless it withstanded the pressure and gave me some excellent firewood!
    • Digging is a piece of cake - due to the relatively long handle who makes it possible to hold it with both hands!
    • After an hour of work it was still razorsharp!
    YAK-PROOF, definitely!

    So: if you don't have a lot of money to spend on a 'branded' survival knife you know what to do now!




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      55 Discussions


      2 years ago

      hey can you make an axe like this as it will make scouts a hell of a lot easier!


      3 years ago

      OMG that will help me and my best friend when we are in the woods.THX so very much.A cool knife it is.

      1 reply
      Street-Wise Irish

      3 years ago

      Why did you choose that length for the blade, great job !!!


      4 years ago on Introduction

      If you think that is the ugliest knife you have ever seen, then you have not seen my brother's..


      4 years ago

      Anza knives use these carbon file steel blades, very durable, my mini Anza has not needed sharpening after skinning 3 coyotes 2 pigs and a deer, all it needs is some oil!


      5 years ago on Introduction


      I don't consider making fun of Bear Grylls as picking on him, I consider it as more in the way of performing a public service.

      Except for the first time I watched it, I can't remember watching a complete episode of Man Vs. Wild. I used to watch portions of the show while flipping through the channels. Despite that and the fact it's been years since I did watch any of his show, I can still remember many instances just off the top of my head where I saw him give advice or doing things that ranged from just bad ideas to this-could-kill-you bad.

      i.e. cooking fish directly beside his shelter in "bear country", building a snow shelter that was actually colder than just lying on the surface of the snow, eating maggots that could contain salmonella or even botulism, jumping off a ledge into a river without knowing how deep the water was, drinking urine.
      --I'm sure if I took some time I could remember more.

      I don't mind that his show was staged (he has publicly admitted this). I don't care that the maggots were actually meal worms, that often just off camera was an RV that he actually slept and ate in. What I do care about is his purporting to be a survival expert and then giving out bad advice.

      I'll continue to be proud of educating people about this.

      1 reply

      Reply 5 years ago on Introduction

      You have made your point and I concede. I don't mind him creating scenarios to teach survival. I don't mind him sleeping in an RV. I do agree with you on taking issue with teaching misleading information.


      5 years ago



      5 years ago on Introduction

      Ok I'm struggling here to post a pic and I already messed this up twice...lol. Let's hope third time's a charm.
      Hubby is a farrier. He uses rasps. They have a smooth side just like what is shown on your knife that I think you could use to create spark for a fire. They also have a rough side and i wonder if some of that was retained on the other side of the knife if it could be used to scale a fish, since most fish are edible (though not necessarily palatable). But I've never scaled a fish before. So pass back a response with an opinion if you have one. Love your projects by the way, I've looked at several.


      5 years ago

      Do you have to use a old file? Because that might be a bit hard to find

      1 reply

      Reply 5 years ago on Introduction

      I don't know if this helps or not. I am the wife of a blacksmith (in NH btw). I don't know nearly as much as my hubby does, but old files are hardened steel, where new files at least in the U.S. are only surface hardened. They are machine pressed and I believe they are fired briefly and then a coating is applied to the surface (all the way around) only. Once that surface hardened bit is worn off the files quickly lose their edge. One could imagine that a file made the old fashioned way would have taken a lot of time! All that being said, there is nothing particularly wrong with using a new file. You may have to sharpen that knife more often, but on the other hand it will be easier to sharpen using a simple rock from the woods, and if you're still in New England there are many MANY good rocks to sharpen a knife with just about everywhere. At some point any knife will need to be sharpened right? What I like about this knife is that it retains the smooth side of the rasp that possibly could be used to make spark. I wonder if retaining a little of the rough side of the rasp could be used to possibly scale a fish? I don't know though, I've never scaled a fish. My hubby must have about 50 used rasps kicking around.


      7 years ago on Introduction

      Nice work! The simplicity is perfect. Perfect for improvisation when minutes count. Sure, one could spend lots of extra time being a blacksmith, but that may not be a luxury. Survival is about adapting. Just ask Darwin.

      2 replies

      Reply 5 years ago on Introduction

      I do blacksmithing, and stock removal from a file takes a lot less time. It's much easier, but more limited. You can only make a knife as big as the file. Then again, there are some files that are about 20 inches long.


      Reply 6 years ago on Introduction

      Not really, the idea was to leave a maximum weight to the tip of the knife to improve slashing. If you want to file with it: feel free!


      Reply 6 years ago on Step 3

      You can use the file part to make sparks with flint and steel to start a fire if need be.


      6 years ago on Introduction

      I want all my survival situations to be like those of Bear Grylls.

      -With a fully loaded RV just off camera.

      Nice knife.

      This isn't a criticism, but I always grind off the striations of the file before I make a knife out of one. I worry about the striation creating a weak point where the blade could break - I could be way off base with this though.