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Picture of From File to Knife (with simple tools)
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A good "bushcraft" knife is a must-have for every outdoorsman.
It's a tool that lasts a lifetime.
Wouldn't it be awesome to make such an essential, lasting tool yourself?

There are many different types of knives and many ways of making them.
This instructable will show you how to make an excellent, inexpensive (<$20) bushcraft knife with simple tools (such as a hacksaw, file, drill and vice).
The design is based on the popular (but expensive) Ray Mears Bushcraft knife.

So if you have a few basic tools and plenty of elbow grease, lets make the [Your Name Here] Bushcraft Knife :)


I have entered this instructable for the Great Outdoors Contest and the I Could Make That Contest.
If you like this instructable, please vote for it!
 
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Step 1: Tools and materials

Here's a quick overview of the tools and materials that I used.
They'll be discussed a bit more later on in the instructable.

-Old file
-Piece of hardwood
-Two-part epoxy adhesive

-Coal
-Forge (something to burn the coal in)
-Air pump
-Tongs
-Quenching oil
-Kitchen oven

-Scriber, permanent marker
-Caliper
-Vice
-Clamps

-Hacksaw
-Lubricating oil
-Files
-Sandpaper
-Drill
-Hammer

Step 2: Finding the right file

The first thing to realize is that "steel" is a generic term for alloys of iron and other elements.
So steels come in various compositions.

Though, not only the composition of a steel determines its properties like hardness, ductility and tensile strength.
Also the way the alloying elements are arranged on microscopic level influence material properties.
So steels with the same composition may have different material properties, depending on the "microstructure" of the steel.
The microstructure can be changed by heat treatment or cold deformation.

In order for a knife to hold an edge it needs to be hard.
Among other elements, carbon is added to make steel hardenable.
So what you need for a knife is steel with a high carbon content.

Old files, but also leafsprings and old sawmill blades are made of high carbon steel.
Most new files are casehardened, which means that only the outer layer is high carbon steel, while the core is mild steel.
So try to get hold of an old file.

There are a couple of ways to verify whether you're dealing with the right file:

Spark test
If you have a grinder, see if the steel on the surface of the file and the steel 1 or 2 mm below the surface give off the same short bushy sparks.
These sparks indicate high carbon content.
If the steel below the surface gives off longer sparks that flow out in straight lines, the file is case hardened.

Hardness test
In addition to the spark test, try to scratch the steel on the surface and the steel below the surface with a screw or drill bit.
In both cases it should be equally hard to make a scratch mark.
If the steel below the surface is softer, the file is case hardened.

If you don't have a grinder, you'll first have to anneal the file (see step 4), remove a bit of the surface, harden it (see step 8) and then test for hardness.
If the steel below the surfaces didn't harden, the file is case hardened.

Break test
Wrap the file into a cloth to prevent steel fragments from flying around.
Secure the file into a vice so just a small portion sticks out.
Then hit that portion with a hammer to break it off.
The material should break readily without bending and the core of the file should be smooth and light grey.
If the material doesn't break readily and the core of the file is coarse, the file is case hardened.

Step 3: Designing

In this instructable I'll be making a knife with a full hidden tang.
The tang is the portion of a knife that extends from the blade and connects the blade to the handle.
Two common tang styles are the full tang and the full hidden tang.
A full tang follows the contour of the handle and is therefore visible.
A full hidden tang extends all the way through the handle, but is not visible.

The height of the thickest part of the handle depends on the size of your hand, but is usually about 30 mm.
So if you want to make a full tang knife, I would advice you to use a flat file that is about 30 mm (or at least 28 mm) wide.

In this instructable I'll be making a knife with a full hidden tang, because with this tang style the size of the handle doesn't depend on the size of the file.
You may either stick to my blade design (and adapt it to the width and thickness of the file) or make your own design (just make sure the construction is the same).

Step 4: Annealing

Materials can only be worked with tools that are harder than the material itself.
Files are hardened.
So before they can be worked with a hacksaw or other files, they need to be softened.
The softening is done by a heat treatment called "annealing".
Annealing involves heating the high carbon steel and cooling it down slowly.
You'll save a lot of work (and tools) if you do this correctly.


Annealing the file

Make a (char)coal fire and bury the file in it.
Make sure there is plenty of coal to surround the file completely.
Blow air into the fire with a pump to speed up the heating process.

The file should be heated to the so-called "austenitizing temperature".
At this temperature the carbon steel is red hot and non-magnetic.

After a couple of minutes of heating, expose the file to see if a magnet doesn't stick to it.
Also see if the file is evenly red hot.
Do this in the dark, as you'll see much more contrast between the different colors of the steel.

If the file is still magnetic and it isn't evenly red hot, bury it in the fire and continue the heating process.
If the file is non-magnetic and is evenly red hot, you know that the fire is hot enough.
Bury the file in the fire and heat it back up again (the file cooled down while it was exposed).
Keep it at austenitizing temperature for about 3 to 5 minutes.
Then leave it to cool down with the fire.



Step 5: Profiling

In this step you will cut out the knife profile with a hacksaw and refine the shape with a file.


Marking out the knife pattern

Print and cut out my knife pattern or cut out your own design.
Then trace the pattern onto the annealed file (workpiece) with a scriber or permanent marker (I used a white pencil, which quickly faded due to the use of lubricating oil).

It's hard to accurately mark out the knife pattern on the grooved surface of a file.
I ended up using a caliper and a separate knife pattern, which I compared the workpiece to as I progressed.


Cutting out the rough shape

Secure the workpiece into a vice in such a way that you can make a vertical cut and that the cut is as close to the vice as possible to reduce vibration.

For sawing material with a thickness of 8 mm or less, a blade with 32 teeth per inch is recommended.
A minimum of 3 teeth should be engaged in the material at all times to prevent tooth breakage.
Install the blade on the hacksaw frame with the teeth pointing away from you.
Tension the blade sufficiently to ensure straight cuts.

Don't start a cut on a sharp edge, or else less than 3 teeth will be engaged in the material.
When sawing, apply a little bit of oil to the blade to reduce friction.
Use long, steady strokes and only apply pressure on the forward, cutting stroke.

Remove as much material per cut as possible.
If the cut is wandering away from where you planned to cut, turn the frame gently in order to twist the blade into the right cutting direction.
If you need to start a cut on an angle (with respect to the material), first make a shallow perpendicular cut that will keep the saw into place when sawing on an angle.


Refining the shape

In this step you'll first use a cross-filing technique to remove the most material and straighten the somewhat wavy edges made by the hacksaw.
Then you'll use a draw-filing technique to clean up the rough surface and flatten the slightly rounded edges produced by cross-filing.

Secure the workpiece into a vice in such a way that you can file in a horizontal plane most of the time.


Cross-filing (straight-filing):

Use a large coarse (bastard, double cut) flat file.
Finer files can also be used, but remove material less quickly.
When filing, you can usually feel whether you're using the right file and the right technique.

Grasp the handle in one hand and the tip of the file in the other, so that you can apply downward pressure.
Place the file diagonally on the edge, so that the file covers a large area.
This ensures that large errors (wavy edges) are corrected.
Move the file from tip to handle, in a direction not quite parallel to the file, to prevent grooving.
Use long, steady strokes and only apply pressure on the forward, cutting stroke.

Usually you have a tendency to file slightly on an angle, as opposed to perfectly horizontal.
Correct this error by changing filing direction by 90° and flipping the workpiece 180° in the vice.


Draw-filing:

Cross-filing usually results in a straight edge, but slightly round in cross-section due to the rocking motion of the file.
Draw-filing is used to make the edge flat in cross-section and perpendicular to the adjacent surfaces and to give it a fine surface finish.

Use a fine (smooth, single cut) flat file.

Grasp the file at each end.
This way you can hold the file steady
Place the file perpendicular on the edge.
Push and draw the file from one end of the workpiece to the other.

With this technique, be careful not to remove more material in the middle of the workpiece than on the edges.
Also regularly remove filings, as these tend score the surface when they get caught up in the file.

Step 6: Making the grind

The bevel or grind of a blade refers to the shape of the cross section of the blade.
Along with the steel type, heat treatment and the thickness of the blade, the grind shape and angle determine cutting performance and blade strength.

In general the steeper the grind and the less material behind the edge, the sharper the blade.
On the contrary the less steep the grind and the more material behind the edge, the stronger the blade.

Furthermore a less steep angle can also be combined with less material behind the edge.
This gives a durable edge, while it reduces friction when cutting.
Examples are a convex grind, double grind and hollow- or flat grind with a less steep secondary grind.

Depending on the application of a knife sharpness is less or more important than strength.
I will make 20° angle sabre grind (giving a total- or "included" angle of 40°).
I think this grind provides a good balance between blade strength and cutting performance for a bushcraft knife.

To reduce friction you may want to convert the sabre grind into a convex grind.


Marking out the grind boundaries

Some knife makers use a jig that keeps the file on the same angle while filing in the grind.
Though you can easily file in the grind without the use of a jig.
To get a grind with the desired angle, you'll need to mark out the grind boundaries.

Measure the thickness of the blade with a caliper.
If you used a file that tapers in thickness, measure the minimum and maximum thickness of the blade.

Calculate the grind width b:
b = T / (2tanα)
with blade thickness T and grind angle α.

Mark out the calculated grind width on the two sides of the blade using a scriber and caliper.

Color the edge of the blade with a permanent marker, so that a scribed line will stand out.
Place the blade on a flat surface.
Scribe the edge using a drill bit with diameter (thickness of the blade).
This way you get a line running along the center of the edge.
If you used a file that tapers in thickness, put something underneath the tip of the blade to compensate for the taper.


Filing in the grind

Secure the workpiece into a vice.

I you want to have a small ricasso (unsharpened section of the blade near the handle), clamp a piece of steel to the blade as a means of guiding the file.

File in the grind on both sides of the blade.
Apply the same filing techniques you've used to refine the knife profile (step 5).
Regularly check if the edge is straight.

Step 7: Quenching and tempering

Now the blade is ready to be hardened.
The hardening is done by a heat treatment called "quenching".
Quenching involves heating the high carbon steel and cooling it down quickly.

After quenching, the steel is very brittle.
The brittleness (and hardness) is reduced by a heat treatment called "tempering".
Tempering is a specialized type of annealing.

There are many ways of quenching and tempering knives, all yield different results.
I will use the most straightforward way.


Quenching

Heat the blade evenly to austenitizing temperature.
Keep it at austenitizing temperature for about 3 to 5 minutes.
Don't heat the entire tang.
The end of the tang needs to stay soft, so it can be peened later on.

Grip the end of the tang with a tongs.
Wear work gloves to protect your hands from the heat

Quickly lower the blade tip first into a heat resistant oil container.
The blade should be at austenitizing temperature when it hits the oil.
Use a sufficient volume of vegetable or mineral oil.
I used about 2L of sunflower oil, but you might as well use 4L or more (for a more uniform quench).

Move the blade around in order to speed up the cooling process.
Leave the blade in the oil until it has cooled down to about room temperature.

See if the blade hardened by scratching the blade and tang with a screw or drill bit.
The screw should skim over the surface of the blade, barely leaving a scratch mark.
It should be much easier to make a scratch mark on the end of the tang.

If the blade didn't harden, either it wasn't at austenitizing temperature when it was quenched or it didn't cool fast enough (assuming the blade was made from a high carbon steel file).

If the blade didn't cool fast enough, try to quench in water or brine (water with 7-10% salt by weight).
Water and brine result in faster cooling (water about 3x and brine about 6x faster than oil).

Only try a water- or brine quench if an oil quench didn't work, because these quenchants are more likely to may cause cracking.



Tempering

The color of the steel gives an indication of the temperature to which the steel was heated.
Remove the scale on the bevel, spine and tang with sandpaper so that the color of the steel will be visible when tempering.

Heat the blade to 175-350°C for about 1,5 hour in a kitchen oven.
A higher tempering temperature yields a slightly softer material with a higher toughness, while a lower temperature yields a harder and slightly more brittle material.
I would recommend tempering in two or more cycles of 1,5 hour, because of the inaccuracy of a kitchen oven.

For example, if you want to temper your blade at 250°C (brown-red):
First temper the blade at 175°C.
If the steel didn't reach a brown-red, temper again at a higher temperature.

Step 8: Making the bolsters

For the bolsters I used the steel that I had left over from the old file.


Marking out the shape and the hole positions

Mark out two ovals measuring about 26 by 19 mm.

The front bolster will need a rectangular hole, so that it fits around the tang.
The rear bolster will need a slightly smaller hole, so that it fits around the narrowing at the end of the tang.

Mark out the rectangular hole in the center of one oval.
Center punch two holes inside the rectangle.
Also center punch the center of the other oval.


Making the bolsters

If you are making the bolsters out of a coarse file, remove the grooves with a file to minimize the seam between the bolsters and the handle material.

Use a drill press or secure the workpiece into a vice.
Use a drill bit with diameter T (thickness of the tang) or slightly smaller.
Make sure to hold the drill perpendicular to the surface of the workpiece.
Apply lubricating oil to reduce friction when drilling.

Cut out the ovals with a hacksaw and refine the shape with a file.

Make the holes rectangular with a small square- or flat file.
You can also leave the hole in the rear bolster circular and make the end of the tang cilindrical.
Both bolsters should fit snugly around the tang.

Make the hole in the rear bolster (very) slightly tapered.
In the next step the bolsters and the handle material will be secured onto the tang by peening the end of the tang.
The end of the tang will expand in cross-section and "fill up" the tapered hole, so that the rear bolster can't slide off.

Step 9: Making the handle

In this step you'll make the wooden handle and assemble the knife.


Assembling the front bolster

Slide the front bolster over the tang.
If the bolster doesn't quite fit over the tang, you might have to enlarge the hole, but for me rounding off the edges on the end of the tang also helped.
If the bolster doesn't readily slide down the tang, place a steel tube over the tang and hammer it to force the bolster into position.


Making the handle

Find a nice piece of hardwood.
I used a piece of about 35 by 35 by 100 mm.

Mark out the rectangular hole.

Use a drill bit with diameter T (thickness of the tang) or slightly smaller.
Make sure to hold the drill parallel to the length of the workpiece.
Drill two holes alongside one another.
If the drill bit isn't long enough, drill from both sides.

Remove the wood between the two holes by gently moving the drill perpendicular to the axis of rotation.
I know this is not where a drill is made for, but it's the quickest way of doing it.

Make the hole rectangular using a small chisel and/or file.
The handle should now fit around the tang.

Saw the wood roughly to the dimensions and shape of the handle.


Assembling the knife

Secure the blade into a vice.
Use aluminium vice jaws or two pieces of wood to protect the blade against scratching during peening.

Apply some two-part epoxy adhesive to the tang, bolsters, and hole of the wooden handle.
Slide the handle and the rear bolster over the tang.
Start hammering on the end of the tang.
Be patient.
The end of the tang should slowly "fill up" the tapered hole.

Let the epoxy cure.


Finishing off

Refine the shape of the handle using a coarse half-round file and sandpaper.
Remove the portion of the tang that is still sticking out with a file.
Sharpen the knife with progressively finer grit sandpaper.
Apply several coats of danish oil to protect the wood from the elements.


Tanks for reading!

I hope you enjoyed it.
If you have any questions or remarks, please don't hesitate to comment!

I have entered this instructable for the Great Outdoors Contest.
If you like this instructable, please vote for it!
1-40 of 134Next »
alcher24771 month ago
Good instrucrions , I have made several file knifes. I do some of the same things you do. The information about the blade grind I am going to try. I am not sure about my tempering of the blade.
lkjhg56one2 months ago

Lol Step 5 is very ironic

seth33705 months ago

this is fun. my dad has about 40 old files. now he only has 26. :)

casvandegoor (author)  seth33704 months ago

Wow, you can start a bussiness ;)

quote494 months ago
I have a couple of questions. Firstly, what type of file was used in the making of this knife? Secondly, could a dremel be used instead of a hacksaw to remove the blank from the rest of the file?
casvandegoor (author)  quote494 months ago
It was a large smooth flat file, high carbon steel (not case hardened). What tool would you want to use? A small grinding disk? I think it is possible, but not ideal. I think a dremel lacks power. You could use an angle grinder.
BigBerland4 months ago

I'm a bit confused as to how thick each bolster should be. You said the handle is 115mm before you peen the end off, then it will be around 110mm. How much space do the bolsters take up after peening?

casvandegoor (author)  BigBerland4 months ago
My bolsters were about 5 mm thick. As long as the tang is sticking out a few millimeters you will be fine. When you have peened the tang, you can remove excess material. I hope this answers your question.
JerryH14 months ago

Problem: the files warped in annealing step. Suggestions?

HannesH1 JerryH14 months ago

Hit it with a hammer.

This is cool, is there anyway you can get rid of the file edges on the finished product?
casvandegoor (author)  justintime19985 months ago
Ofcourse: you can just file them off ;)
Flash675 months ago
Wow! You did an amazing job on this i can see you really put your time into this instructable and I can tell you very passionate about this! I'm gonna have to try this someday. This instructable is also a very good example of good instructables I want my first instructable to be like this:)
casvandegoor (author)  Flash675 months ago
Thank you very much :D I'm glad that I've inspired you to make good instructables.
dhakim made it!8 months ago

Finally finished! Thanks for the idea...it was a great learning experience.


file knife.png
casvandegoor (author)  dhakim8 months ago
Awsome! Nice Work!
Emsaid8 months ago

Great ible! Just finished annealing mine, I'll post a picture when I'm finished with it.

casvandegoor (author)  Emsaid8 months ago

Nice! I'm curious how it turned out.

Mattrox9 months ago

This is awesome! I love the finished knife and how you used fairly everyday tools. Thanks for posting!

clockworkfish9 months ago

Such a great job on this!

Johnhall1410 months ago
Good instructable : )
casvandegoor (author)  Johnhall1410 months ago

Thanks!

=)

Advar12 months ago
Nice 'ible! Question: If one wished to make a hand ax, with a stronger edge, what griding angle would be best with a dremmel? For a camper friend next Xmas.
The block is 6"l, 4"w 1\2"t.
casvandegoor (author)  Advar12 months ago
Thanks! I'm not an expert, but this is what I found: The grind angle ranges from 12 to 20 degrees (so the included angle ranges from 24 to 40 degrees). It depends on what you want to do with the axe. For carving you'll need a steeper grind angle (12 to 15 degrees), while for chopping (hard) wood a less steep angle is preferred.

http://www.axespecialists.com/axe-sharpening
http://www.gransforsbruk.com/en/axe-knowledge/caring-for-your-axe/sharpening/
Advar casvandegoor12 months ago
So I'd want to use 12-15°. Thanks!
ZakSett1 year ago
Nice work many thanks, tips from expert , well explained
mykiscool1 year ago
Prisoners everywhere hail you as their hero! Just kidding though, nice instructable.
casvandegoor (author)  mykiscool1 year ago
Haha, thanks!
That is very interesting. I think if I make one I will just cut off the tang of the file, and make a very straight knife with the old file surface for grips, and finger grip indentions. No woodwork would be necessary then.
casvandegoor (author)  Yard Sale Dale1 year ago
That's also a possibility. Good luck!
flatboat1 year ago
As a metallurgist, it is a real pleasure to see someone on these forums give well thought out useful and accurate knowledge, in a clear and concise fashion, to people wanting to do a good job! Well done!
casvandegoor (author)  flatboat1 year ago
Wow, thanks!
I just published my own knife building ible. Not nearly as well worded as yours though. Good job.
cjones921 year ago
"Forge" sort of throws this a bit out of the "basic tools" realm, don't you think? Heh heh!
casvandegoor (author)  cjones921 year ago
By "forge" I actually mean anything you can burn the coal in. So in this case it can be a barbecue, a couple of stones or a hole in the ground. You can even heat the steel in a simple campfire as well.
I am using this as a forge for my knife(s), I would suggest two burners though.

https://www.youtube.com/watch?v=jBVa2bw3r_k
jyxk1 year ago
great!I want to make a knife like this!bushcraft
cjones921 year ago
Cool (er, uh... Hot?) project!
casvandegoor (author)  cjones921 year ago
:)
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