Blacksmithing from a woodworkers perspective #2: Forging a iron age knife - first wood working tool made

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Blog entry by mafe posted 04-24-2016 11:44 AM 2616 reads 0 times favorited 19 comments Add to Favorites Watch
« Part 1: Anvil stand Part 2 of Blacksmithing from a woodworkers perspective series Part 3: Crooked and hook knifes - from steel to tool I »

Forging a iron age knife
first wood working tool made

Will jump right in to my first blacksmith tool making project in the work shop, I decided it should be the most basic tool for a Woodworker, Lumberjack or Lumberjock – a knife. As a Dane I felt it made sense to start here, this type of knife are often mentioned as Viking knifes, but they are dated back to the iron age.
(The truth is that even I thought it was a Viking knife type).

The type has ben found here in Danmark, in a place called Dejbjerg and are dated to 100 ad.

I start in our time…
The knife will be made from a piece of car spring steel that I found in the street on my way home from the workshop one day.
Car springs have a relatively high content of carbon and are clean, this makes it ideal for forging tools.
You need a high carbon content of the steel to be able to harden it like this.
Steel can also be bought from a commercial seller and are actually relatively cheap.

Here the iron are getting up to forging temperature in my wonderful new gas forge.
The forge are amazingly fast to get the steel there and like this forging is a dream.
Also you don’t get the steel too hot so easy, since you can control the temperature by the flow of gas.
If the iron gets to hot it will melt or for the carbon steel it will ‘burn’ sparkle off.
If not hot enough you will not be able to form it and the steel will get stressed.
You don’t need a fancy gas oven, you can use coal or make a soup can forge really cheap, the web is full of these getting started videos. I am thinking of making a soup can version just for the fun of it, if you can get hold of ceramic felt, this oven can be made in half a hour, otherwise you can make a more at hand version with Perlite.
Look at the video here:

The key is in the color, here you can see them.
Found this online.

A simple hammer is all I have for now for the heavy part, so this will have to do.

But the workshop are set up for forging now.
I decided to protect the wood floor with aluminium plates before I went on and on the floor you see a bucket with oil for the quenching process. Yes we should be ready to go now.

Once the steel is hot, it’s time to hit it with the hammer.
The anvil works great and the tools are at hand when needed.

In and out the forge.

Hammering it to shape.
I’m really enjoying this process, everything are working fine in the flow.
Perhaps I need to place the forge a little higher so I don’t have to bend for looking inside.
The color you see on the tip is a good color for working the steel, here it’s soft and will be formed without cracking.
But you relatively fast get a feel to when it makes sense to form it.

Here you see a piece of spring and what it becomes.
I’m quite pleased with the way it works out, for a beginner I feel happy.

Soon this is where I get to.

I smile and look at the new work area.
Even possible to take a rest here on goat skin, what more can a man ask for…
I leave the blade on top of the forge to cool down slowly.
Like this it will become soft and I can work in it.

Once it is cold. I start to shape the blade profile and even out the taper with a file.
I have done as much of the shaping I could manage on the anvil.

But I found the steel a little hard, so I re heated it to red hot and then left it in the forge to cool down, this time waiting a good hour before I took it out.
(I must have been to quick before, then the steel hardens up, so patience is the key word here).

Then it was much easier to work with.
I finished it up with sand paper, not too carful since I wanted this to be fitting the raw steel.
Don’t finish the edge here, leave it stump, like this it will not get wrapped when heat threating it.
Some will at this time do one or two runs where they heat it to red hot and then leave it to slow cool, like this the blade will be at rest, the tensions will be out of the steel, I will go directly to the tempering, I believe in a small knife like this, it will not be an issue, but time will tell.

Then back in the forge, warm it up again.
This time back edge up and the whole blade gets heated, but the handle stays cooler to keep this soft.

Then with a magnet test if the steel is hot enough, once it is no longer magnetic, it is more than 850 degree C and ready to be put in the oil.
I use canola oil it was cheap, easy to get and smells like cooking when used.
At my first go I did not preheat the oil, this resulted in a blade that was not hard enough, so I made the oil hot and then did it again, this time it worked and the blade seems to have a good hardness.
(I scratch it with a file and it leaves no marks).

Then while it’s still hot I give it some bees wax, this should help to rust prevent the blade.
(Advice from fellow LJ Brinth, thanks).

After sharpening the blade looks like this in the daylight.

I make a quick wooden sheath for it.
Just a sandwich construction glued together.
Thas the shortest wood working description ever here, lol.

Then home to make dinner for my daughter and girlfriend.

And to use the heat from the oven to temper the blade.
I give the bred five minutes and the blade one hour at 200 degrees C.
Before you temper a blade it is tense so it can snap if you hit it with something hard, the tempering makes it relaxed and flexible, so it is a process you don’t want to skip.

For dinner we had marinated halibut.

And a burger.

Ok back to the tool making.
Here the blade is out of the oven and left to cool down on the pan.

You can see how the blade got the straw yellow color on the edge, this means that it is tempered rigt.
Also I gave it a wax again for the rust protection at this stage.

This is it after the final sharpening.
I am happy and a wee proud, now I have really gone full circle in the little shop.
Life is sweet and I feel lucky.

And finally in it’s sheath.
Now this is a wood working project. ;-)

Hope this post can inspire others to make their own tools, after all this is why I take a detour out the black road now.

Best thoughts,


-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

19 comments so far

View Jim Jakosh's profile

Jim Jakosh

16797 posts in 2525 days

#1 posted 04-24-2016 12:31 PM

That was really a neat way to make the knife. Thanks, Mads.


-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View Brinth's profile


60 posts in 343 days

#2 posted 04-24-2016 01:07 PM

Nice description.
I have some old Wood tools (til udhuling af træsko) from around 1850 you can try to copy. It will fit well inside your shop… and be a funny “future” wood project

-- Brinth, Denmark - "nothing is impossible and everything goes; if you have the will (and the time) to do it"

View lew's profile


11263 posts in 3175 days

#3 posted 04-24-2016 02:07 PM

Thanks for the wonderful tutorial. The knife looks like it turned out fantastic- and the dinner looks delicious!

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View Jim Rowe's profile

Jim Rowe

917 posts in 1732 days

#4 posted 04-24-2016 03:49 PM

You are a very talented and lucky person! Thanks for taking the time to share your progress here.

-- It always looks better when it's finished!

View shipwright's profile


7086 posts in 2218 days

#5 posted 04-24-2016 03:58 PM

You are making me want to do this Mads but I have so many things I want to do. ....... I guess I will enjoy you doing it.
I also share your love of food and cooking. I’ll be taking a cooking course in Lucca, Italy for a week in the fall. I will think of you.
Nice knife and a very nice sheath too.


-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View pbyrne's profile


80 posts in 2112 days

#6 posted 04-24-2016 04:37 PM

Thanks Mads for your inspiring post. I’m still watching for an anvil, I am patient it will come to me.
I look forward to the day I can forge my own tools.

View tyvekboy's profile (online now)


1307 posts in 2433 days

#7 posted 04-24-2016 04:38 PM

Great description. Thanks for sharing.

-- Tyvekboy -- Marietta, GA ………….. one can never be too organized

View Tony_S's profile


597 posts in 2503 days

#8 posted 04-24-2016 10:54 PM

Your killin’ me Mads!

I’m a bit of a knife junkie…..I LOVE it! The character…the handle…simplicity at it’s finest.

Can’t wait to see more from you!

Looks like you cook with the same passion you do everything else with…

-- It is the mark of an educated mind to be able to entertain a thought without accepting it. Aristotle

View madts's profile


1662 posts in 1760 days

#9 posted 04-24-2016 11:04 PM

Nice Mads.
You are just over the top.


-- Thor and Odin are still the greatest of Gods.

View peteg's profile


3806 posts in 2243 days

#10 posted 04-24-2016 11:29 PM

Always love the journey you take us on Mads with your creative ventures, love the knife, that’s a great little forge set up you have there.
After seeing your lovely meals I’ve gota go I’m hungry :: )))
cheers Bud

-- Pete G: If you always do what you always did you'll always get what you always got

View NotaJock's profile


35 posts in 519 days

#11 posted 04-25-2016 12:01 AM

That little knife is a cool tool.
I’m glad to see the new forge is working out for you.
Your anvil is a much different shape/style than I see in the US, is that common in Denmark?
I use a 3# coffee can full of Perlite for annealing small tools.
Since aluminum melts at a much lower temperature that steel I hope the aluminum going to rob enough heat from a dropped piece of cherry red steel to keep the steel from burning through. Is a test called for?

-- Mike in SoCal

View Don W's profile

Don W

17876 posts in 1987 days

#12 posted 04-25-2016 10:05 AM

Always an adventure Mads!

-- Master hand plane hoarder. -

View stefang's profile


15512 posts in 2754 days

#13 posted 04-25-2016 10:48 AM

Well done Mads. A nicely designed ‘antique knife’ to be proud of. Lots of fun seeing how you did it.

-- Mike, an American living in Norway.

View Roger's profile


19714 posts in 2224 days

#14 posted 04-25-2016 11:50 AM

Very snazzy Mads. Food looks very yummy also

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed.

View Brinth's profile


60 posts in 343 days

#15 posted 04-25-2016 03:33 PM

Your anvil is a much different shape/style than I see in the US, is that common in Denmark?

That anvil is not so common in Denmark.
The anvil is a “traviling” version of an anvil. In old days when they have to build mills, big Buildings, something inside forests, and so on the workers moved the anvil to the working site. You just need to make a hole in a piece of wood and then you are almost ready to Work.

Last time i were seeing it in use were this september. A lot of “naver” worked on reparing a old windmill on a museum. I to worked with them that 10 days but not with the mill.

A “naver” (wervanderen) is a educated craftsmann there walks 3 years and 1 day on the road to learn more of his education. They are not allout to come closer to home than 50 km and is not alloud to have a phone. They have to walk but is alloud to ride in a car as a passenger. They are only alloud to pay for transport by plane, boat or bridges. They Work mostly for food and sleeping. (depends of the rules in the country there Work in) They are only alloud to Work max 3 months on the same worksite. (if you follow the most common rules (the german).
From Denmark we right now have 3 “navere” walking. 2 carpentes and a blacksmith.
All kind of eudcations (tailors, Goldsmith, Carpenters, blacksmiths, ...) is alloud to be “navere”. But you have to start before you are 30 years and no kids. You can reconice the “job” on the colour of the dress. Black trousers is working with Wood.
I have meet some “navers” there have been in US. But it is a tradition mostly from germany.

-- Brinth, Denmark - "nothing is impossible and everything goes; if you have the will (and the time) to do it"

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