Hi everyone. Here is another video.
With blacksmithing especially as a one person operation, I frequently need to make more
tools. I just started making some kitchen knives again and realized
that I know longer had dies for the blacksmith helper to isolate metal.
I usually rely on the dies you see here which are round but sometimes I need a very sharp
transition to forge a right angle, in this case for the bolster of the knife - something
like what you see in the picture.
The blacksmith helper makes a lot of tasks much easier but making the dies is not something
I enjoy. In this case, I want to make split dies. Half of the dies are to forge in a chisel
shape and the other half will just be completely flat. You will see later in the short demo
why I need this.
I am using mild steel bar which is 3/4in thick and 2 1/2in wide. The total length counting
both dies is about 7 1/2in.
The bottom die is 2 1/2in long and the top die is 5in long.
As I am looking for a 45 degree angle, I am marking a line 3/4in away from the cut end
of each die.
The main challenge will be to cleanly remove the extra metal. I am thinking that I will
establish the separation between the chisel and the flat die with a saw and then grind
and file off the excess metal.
To do that I am clamping the die at a 45 degree angle into my leg vise and then will try to
cut with a metal saw horizontally to the floor.
Let's see if I can do that.
This looks pretty good and now I have a clean separation that allows me to take the die
to the grinder without the risk of grinding into the flat part of the die.
Overall, I was quite surprised how quickly I was able to make these dies. I had expected
it would take much longer.
The only work that is remaining is to chamfer and round off the sharp transitions and then
I will try to case harden the dies.
With case hardening, the outer surface of the steel is carburized and then quenched.
This creates a hard outer shell that hopefully will mean that the dies are going to last
longer.
Before I can do that though I need to make sure that all surfaces are free of scale or
at least the working parts of the dies are clean.
This looks quite good.
I need to forewarn you. I almost never case harden and never heard a sharp snapping sound
when quenching. So, let's see how this goes.
The principle behind case hardening is carbon migration. At high eats, carbon in the steel
will migrate to areas of less carbon. So once the dies are
glowing orange I will apply a powder that is very high in carbon and then let it soak
in for a bit. In theory, some of the carbon should migrate into the surface of the steel
and lead to a carbon content high enough to harden the steel - at least right at the surface.
Oops. This is what happens when not using the right tongs.
Fortunately, since this is mild steel extra quenching is not really a problem here.
Once the case hardening powder has been applied, the steel needs to soak a little bit to give
time for carbon migration.
During the quenching I have been told that it's possible to hear a crack but I have never
heard that myself. Hardened or not these dies should work just fine.
You can see from how I am holding the tongs, that these tongs are not a good fit for the
thick bar as well but since this was just a one time operation I did not want to adjust
them - even though it would have just taken a few minutes.
For the bottom die, I don't plan on dropping it again and am just repeating the steps I
followed for the top die.
Before testing the dies in the blacksmith helper, I want to clean off some of the scale
that built up during case hardening.
Here we go. Let's test them out. I will heat up a small piece of round bar and use the
chisel part of the dies to isolate material and then use the flat dies to forge the transition
flat. This should lead to a square corner.
Here you can see how the 45 degree angle leads to a very sharp transition.
Now, let's forge it flat.
To get this right, I need to align the transition point with the square dies.
Alright, for the purposes of this demo, here is the shape I was aiming for.
This was not really the video I had planned on making but with this tool finished I can
go back to making a really cool little kitchen knife.
You will see it in my next video. The forging is all done and I just need to put the handle
scales on and finishing grinding it.
As always thanks to everyone on Patreon. You can check out in progress pictures and updates
there.
I am recording this voice over during very uncertain times. In my county we just received
a shelter-in-place order to slow down the spread of covid-19. Please, take good care
of yourself and your family. I will see you next time.