Hello dear friends! I’m George (Yorgos) Mallioras.
Along with my brother Andreas we construct grills and ovens.
Our passion for grilling and also cooking is great and we share it with you
on our Youtube channel “Grill philosophy”
and also our Facebook page “Greek bbq club”.
Every Thursday and Tuesday we’ll be here to give you a new grilling or oven recipe,
but we’ll also have a few extra episodes, like this one
to show you the tools we use,
grilling tips,
and other various topics.
So, today,
we’ll tell you about a historical knife, the “kopis”,
its history, and its manufacturing process.
Happy grilling everyone!
Hello again! Hello! Sifis has joined us again today
to talk separately about each knife in our collection, the knives we use here.
First of all, they are historical knives
with a long-standing presence in the region of Greece.
In particular, the “kopis”
has been found as early as the 6th century BC in Greece.
Alexander the Great used mainly the “kopis” sword
during the war against the Persians.
The cavalry and also the infantry used this weapon
that was designed not to stub, but rather to cut.
- This way. 
- Like a cleaver.
A popular tool for us…
Of course, Alexander the Great, with this sword, reached far into…
- far into Asia.
- Nepal, Afghanistan…
Where, in Nepal, the natives, the Nepalese
admired this weapon
and probably based on it, designed the Kukri knife,
the Nepalese Kukri knife,
which is a shorter version of the “kopis”
used by the Gurkha in Nepal.
Ancient Iberians also admired this design
and replicate it,
although they made it longer and thinner
to be carried by the cavalry, and they named it “falcata”.
-Yes, yes…
So, this is…
This is a famous tool
in the Ancient World.
And we’re proud that it has its origins in Greece.
It could deliver a blow with great momentum.
Yes, because the center of gravity of the blade was towards the tip.
And it’s a knife that when you hold it in your hand,
you feel that it comes down effortlessly,
with its own force.
This is how I felt, when I held it in my hand for the first time in Sifi’s lab,
and I’m referring to the original “kopis” sword,
and this inspired me to make a shorter version of “kopis”
that can be used as a cause of peace,
a tool that helps the griller to cut the “kontosouvli” (spit-roast)
and to hack small bones.
That’s why we have a different kind of sharpening here,
where it’s very sharp,
and a different kind over here
for hacking bones.
Without spoiling the knife edge,
because the front part isn’t very sharp.
- Yes.
Exactly.
It's like a cleaver.
The grip is made of wood.
It’s made of walnut wood,
like the traditional “kopis” knife.
The traditional “kopis” was made of walnut wood, chestnut wood, or oak wood.
Hardwood.
- Common hardwood trees in Greece.
- It’s common in Greece and it’s very strong.
It’s also made of bronze. It’s made of solid bronze.
On the back, it has
a hawk’s head shape with the beak,
of course, the hand protector is missing,
which secured the hand,
so that it could stay in place during battle.
And it was used as a weapon, too, for punching the enemy.
Like that. 
– Yes, for heating this way.
It’s particularly hard to make a knife like this one and Sifis will tell us more about it.
Yes, that’s exactly how it is Yorgos.
This knife has many different angles and curves, as you can see,
which are very tricky,
and we must make them symmetrical on both sides,
they must be the same, identical.
This raises the level of difficulty.
Considering it is 6mm-thick.
The blade is indeed 6 mm-thick and it’s made of D2 steel,
which is industrial tool steel- a very strong form of steel.
This length of this knife is approximately 36 cm.
- Yes.
If I remember correctly,
that’s how long it is and it weighs 670g,
it’s kind of heavy. It's a cleaver.
It comes down with great momentum.
That’s right, like a cleaver does.
You can use this part right here, which is closer to your hand and it’s lighter,
for cutting meat easily, for slicing meat
And this part where the center of gravity is at the front
can be used, because of its momentum, for hacking bones, joints, etc.
You can see now that the knife is shinny,
but when you have the blade on its original form,
it’s totally different from this.
- Not even close.
I’ll bring a few unprocessed blades sometime
to show you how a blade is originally before getting at this final stage.
We’ll show you some of that footage now, in this video,
which we got from the studio during the process of making this knife.
That starts with tracing the shape on the blade with a marker,
a white marker,
then cutting it with a circular saw.
Everything is handmade. They’re handmade knives.
In Sifi’s workshop
Well, I’ve just arrived in Sifi’s neighborhood.
I have my camera on.
He doesn't know that I have arrived yet.
I hope I’ll catch him off guard. He’s on something right now.
I’ve arrived.
Here already?
I’m here and I’m recording!
That early?
And you’re recording me while I’m working!?
What a surprise! Come in.
What’s this? What’s this?
This is a movie replica sword from The Lord of the Rings.
Aha, I’ve watched it multiple times.
It’s the sword of Thranduil. I’m making it for my personal collection.
Nice tool!
It’s ready. I’m just polishing the blade.
Yes. So, order coffee first.
Nice.
Firstly, let me welcome you.
Thank you! I’m happy to see you again!
So, I wanted to surprise you.
You did!
I waited outside for a while and I sneaked in.
You did surprised me.
So, let’s have some coffee first.
- OK.
Then, we’ll continue.
Hello from Sifi’s lab this time.
Hello from me, too!
I’ve been here many times before
and I came with my camera today
to shoot a few videos.
Sifis will show us
how he makes the “kopis” knife.
Is this the material you use?
We start with the unprocessed blade, which is the raw material we use
to forge our knife.
This particular type of steel is Swedish tool steel
from a company called Uddeholm.
I see.
After we trace on the blade the shape of the knife we want to make…
and we’ll show you how we ended up here,
starting with the template we have,
which was my original design.
I worked on a template that Sifis had,
but before we end up with this particular design,
we drew many different versions on paper
and finally decided on this one.
We thought about it a lot.
Yes, a lot.
We tested it many times with our hand to check its grip.
Sifis will show us now
how we go from this blade to this one,
that’s the first stage
and the easiest one, I would say.
In the end, this is what we get.
Right! That’s the final stage,
but to get here,
Sifis has to work on this for about a week,
or even longer,
provided that you work on this exclusively.
If I work exclusively on this project
for several hours a day,
it will take roughly a week to make it.
It’ll be ready. Yes, it’ll be practically ready.
Luckily for him, although I’m not that lucky, since I have to wait longer,
there’s a lot of work
and let’s see the process.
I want you to tell us a few things
about the process apart from the design,
about the hardening and tempering…
We’ll talk about everything and show everything..
The shaping of the metal, the hardening and tempering process, the metal hardness scale…
everything you need to know.
So, let’s watch a few shots
of this first stage,
which is required to go from this to the one we have here, and then here,
Let’s go. then.
Our first task is to draw the design of the knife we want, on the blade
that we want to use.
And this template that you see here was made
after a lot of consideration and many adjustments.
Am I right, Sifis?
Yes. It’s specifically designed to work as a meat cleaver.
I gave him a hard time, though, before we get the final design,
but it was worth it.
Yes, it ended up being a great tool.
This is the first stage
of the making process of “kopis” knife.
I don’t know if you can see it.
I do, because it glows.
It doesn’t show up on camera, but here I’ve drawn the “kopis” design.
It’s ready. It has exactly this shape.
Good.
Now, we’ll cut it with the circular saw.
We cut the umbilical cord.
It’s ready.
Wait a moment.
What about these imperfections?
These?
Yes.
We’ll remove them all. Of course after a lot of work...
We started with the circular saw,
then we used the grindstone,
and now we’ll continue with the grindstone, then we’ll go with the belt grinder.
We removed this part piece by piece;
the blade was up to here at first and we cut off these, piece-by-piece.
Here they are, and there are even more.
Even the smallest mistake, guys, can ruin the blade for good.
It equals total disaster.
We have to throw away this material and start all over.
During the whole making process,
I think there are numerous steps, Sifis, that are…
tricky? …
Tricky.
So many!!
And if things go wrong at the beginning of the process, it’s no big deal.
Yes.
But if things go wrong towards the end of the process,
as you can tell, the greatest loss is all the hard work.
We have to be very careful
and pay attention to detail,
since if we don’t drill the holes right,
we cannot attach the blade to the handle properly,
it will be loose, and it will easily fall off.
I see...
Overall, the structure should be robust,
no part should be loose.
Everything must be tightly connected.
Of course.
The first hole is done.
This way, I suppose, you’ll drill the rest of them with the matching drill bits.
Do you use any type of lubricant?
Yes, I use some kind of liquid to keep the bit cool,
so that it can drill more easily.
This is the heat treating oven, Sifis,
which you use for hardening.
Tell us a few things about this oven.
This is an electric heat treating oven that has a temperature controller.
It’s a great piece of equipment
that I bought from San Marino.
That’s near Italy.
I did my research and I believe I’ve found the best machine
for small-scale production of knives.
What about the other type of furnace?
That’s another technique used to make a different type of knives.
It’s for non-stainless steel knives,
which can be heat- treated with less detail.
The knives we make are stainless steel knives
and require an electric heat treat oven in order to heat the blade,
for at least 20 minutes,
to a high temperature, that is always constant
± 2 degrees,
otherwise we won’t get a good result.
And this is what the oven does.
It regulates the temperature for as long as we want and keeps it constant.
Moreover, if we don’t want to have any problem hardening the blade,
we must wrap the knives in stainless foil,
to protect them from the oxygen in the air,
which can burn the carbon of the blade.
So, when we want to heat treat a stainless steel knife in an electric oven,
we wrap it in stainless foil,
making an envelope-like case,
and we add fuel to the envelope,
to burn the air that is trapped inside the envelope.
In other words, we want to heat treat the knife under oxygen-free conditions.
It’s a long process.
Yes, that’s the case with stainless steel knives.
Non-stainless steel knives can be heat-treated in a charcoal furnace, a gas furnace,
therefore, under air conditions without protection.
SInce they don’t have to be heated for as long
and they don’t require accurate temperatures.
Stainless steel knives are a totally different thing, much more difficult to make.
So, after we wrap our knife in stainless foil
And I assume they require a standard temperature, right?
You mean stainless steel knives?
Yes, it should always be over 1000°C
Regarding my creations, the temperature range
is between 1030 and 1150 °C
For half an hour or 20 minutes, at least.
So, we’re wrapping the knife in stainless foil,
we’re adding fuel inside,
such as a small piece of paper, wood or even powder.
We’re sealing the edge, creating an envelope, and we’re placing it inside
the oven on the rack.
We’re closing the door,
we’re adjusting the desired temperature, and the heating process begins.
We don’t adjust the heating time ourselves.
There is a program for setting heating time beforehand
on the oven’s controller
and we only have to select the program we want and the controller will execute it.
It’s like selecting a program in a washing machine.
What happens after the blade is heated?
After the knife is heated,
we’re using a pair of tongs, not our hand,
we’re removing the envelope.
Do you submerge the blade in liquid?
No. We use liquid for non-stainless steel knives.
The quenching medium for stainless steel is air.
We’re placing it on the rack,
where there is a fan that produces pressure,
and we also have this device, which produces more air.
I haven’t seen this before.
That’s because a stainless steel blade must cool down
in no less than 30" and no more than 2 minutes,
not rapidly.
This type of alloy requires a certain treatment, otherwise the blade will break.
It'll break...
It needs ½ to 2 minutes to cool down
so we have enough time, personally,
I need 1 minute for this stage.
This means I’m in the middle. I’m ok.
Are we done after this?
No, we aren’t done yet.
After this, we must temper the steel.
Yes, otherwise it may break like glass.
- It's too fragile.
It may break like glass.
Plus, stainless steel blades are susceptible to internal cracking.
This means that if we don’t temper the steel,
its crystal structure
can crack on its own.
if we skip tempering.
The steel cracks internally
without us seeing it
and after a while the whole blade breaks into two pieces,
leaving you wondering what happened.
- I see.
- So, we must temper the steel, stainless steel or not.
Oh, I see, Sifis.
Then, we take measurements, right?
Then, to check if we’ve done it right,
if everything is OK,
we should check its hardness.
For this we use a hardness tester.
This is our hardness tester.
Look how we’re measuring the blade’s hardness.
We’re placing the blade on the working table
and we’re lifting the table
until it touches the indenter.
We’re turning the wheel
to make this needle turn around three times.
It’s ready.Our knife is 60 HRC,
Yes.
60 on the Rockwell C scale.
You can see it here.
It’s the black digits.
And we should point out that going from 59 to 60
is a big difference.
It’s much easier to go from 50 to 52-53
than to go from 59 to 60.
I see.
We are near the limit of hardness there.
This is a high hardness knife.
It could also reach 61 HRC
or even 61.5 HRC
but for a kitchen knife, we avoid higher numbers,
since it would more difficult to sharpen our knife.
60 HRC is more than enough for a kitchen knife.
Factory kitchen knives are 52-56 HRC.
This is 60 HRC.
I see.
And from 56 HRC to 60 HRC?
That’s a huge difference.
This means that this particular blade
with continuous hits can cut in half a knife that is 56 HRC.
Such huge is the difference.
I see.
And the final touches. We’re polishing the knife.
We want to get a mirror finish on our blade.
Of course, this is my “kopis” knife.
I brought it with me
to show you how to mirror polish a knife, with specific bands.
Will you tell us a few things about them?
Yes. These bands are specifically made for polishing a knife’s blade
and we always use them along with these polishing bars.
These right here.
That’s the blue one
and we have this brown one, too.
The brown bar is thicker and the blue one is thinner.
They contain emery,
and the way we rub them on the band,
makes it work as a sandpaper. It cleans and polishes the blade.
You have to be careful, I suppose.
This machine right here
is the most dangerous one in the whole lab.
If I make the mistake to place the edge on the opposite side,
the blade may get stuck on the band,
and then the band will drag it to the opposite direction and it will hit me on the face.
You don't say!
It will go under the machine and it will end up on my face, it'll kill me..
This is the most dangerous machine in the room.
It’s ready.
One of my favourite knives
based on the sword of Alexander the Great.
Special thanks to our knifesmith Sifis Nikoloudis
