Coke Forge and Sword!




First I will show you the long-ish ground forge, what i used, how I put it together and lit it, then how I made the sword blade (note not full tang) and handle ect.

Step 1: Materials

!!Important lots of heat and fumes given off so out side is a must for this type of forge, when the worked mettle is taken out it will be red-white hot, you will feel the heat from a distance so don’t let it get any where near your or any ones skin or body or it will hurt, a lot!!


The materials needed for constructing a non-permanent forge depends on the size and shape, this forge was made for the job of forging the blade of my sword, so I will list the materials as if u was replicating this exactly (or kind of).

•Building bricks with 2-3 holes, x8
•Solid building bricks (sand stone bricks not as good due to the heat) aprox x40
•Roofing tiles x5
•Breeze block x1
•Slabs x2-3 (depending on size of slabs)
•Hair dryer x2 (similar powers)
•Soft clay about 1kg

Sword (if making)
•Steel to work, suggest part of a small car leaf spring because of the high carbon factor and easy to work size another easy option is a car coil spring cut up. But for testing any steel can be used, a good thing to play with is reinforcing rods as you can make tongs for later use with the forge
•Length of reinforcing rod or other steel rod, 1.5-2 cm diameter and about 23 cm long.
•Steel plate about 4cm x8cm for hand guard, can use a section of leaf spring as I did.
•Wood for handle, 26cm x20cm and 1.5cm in thickness, suggest a hard wood because it makes turning a smooth finish easier.
•Bolt aprox 2.5-4cm brass or steel depending on preference.
•Washer, fancy as it will be on the hilt or but plane is fine.

Tools needed

•Making the forge
oBrick chisel

•Working the forge
oBucket of water incase something happens (note tern off power to the hear dryers first, sounds silly but funny things happen when you panic).
oWater but for quenching, if you need to make hard brittle items.
oHeat proof gloves that reach up the arm.
oTongs, I found mole grips very useful but longer reach tongs may be found safer for retrieving smaller items from the forge.
oA solid lump of flat cast steel or iron. I used the back part pf a vice sat on a wall, this is far from ideal (just look at picture..).
oSelection of hammers with different heads and weights, tack up to club.


•Bench vice, on a bench this time.
•Lathe for turning handle, not a must but quicker than trying to plan it.
•Rounded chisel.
•Angel grinder for first sharpening and fine tuning.
•Bench water-stone, not a must but gives a better edge.
•Drill with sander attachment and a buffer attachment.
•Hacksaw .
•Tap and die set.

Step 2: The Forge - Layout, Construction and Lighting

1. First thing, find a good spot to set the forge up, not under any thing, where it wont have to be moved, but still shielded from any winds.

2. Place the slabs on the floor adjacent to each other with the breeze block at one end to act as the back.

3. This next part is the hardest to describe it’s the making of the air ways, the object is to have even amounts of air flowing into the forge all the way along its length on both sides. Lay the solid bricks along the edge of the slabs on there sides from the back to the front on both sides of the slabs with a gap for the air in let in the middle.

4. Now place the building bricks also on there sides with the holes in them approximately 8cm away from the other bricks laying them from the back to the front.

5. To cap of the air way use the solid bricks laid so they overhang on top of the other bricks.

6. Lay another course of bricks on the inner wall to make it higher, some chopping of bricks will be required to make them fit. Studding the pictures will help but in the drawn one I have it with 5 rows of bricks when it should have 4 but this make no difference the principles are the same. It is beneficial to have a lip at the front of the forge to stop the coke from falling out.

7. The outlet holes that are most near the air in let need to be closed up slightly, using the clay make a rim around the holes halving the diameter and feathering off as it gets further away from the air inlet.

8. Rolling the clay into strips seal the bricks with the clay so that little air can escape. Do not attach the hair dryers yet.

9. Have the tiles near by as they will act as semi lid to keep the heat in once the forge is going. Set out the tools you will be using, the bucket of water, the water but, the mettle you will be working on and the thing that you have chosen to work the mettle on all out so that it is in easy reach.

10. The best way that I found to light the coke is to put the coke in that you need (up to the first two layers of bricks), then to burry some soft and hard wood in the coke then build up a layer of wood on top of the coke so that it is higher than the top brick. To light use lighting fluid or diesel, do not use petrol or methonal as they are far to combustible and will go out before heating up the wood so it burns properly.

11. Doing this should make a fire on top of the coke and once the fire has died down, heated up the forge and the coke underneath, attach the hair dryers and seal with some clay once attached play with the settings until you get the right heat. Don’t have them on full if it isn’t in use for a bit because it will burn up the coke and having them on full power may make the forge to hot as it can reach temperatures that will destroy the bricks and the mettle you are working on!

Step 3: Forging a Blade and Making Good

Take the (suggest hi carbon as lots will be lost in the heating) steel cut it into a workable size, but have the mass so that when it is drawn out it will be approximately 50 cm long.
Using tongs place the steel into the forge, put the tiles over the top still leaving gaps. If you have never done anything like this before you may now see in a new light why smithy’s are depicted with arms like cow legs, it takes some time and effort to draw out that steel and shape it. When it is heated red-white hot it can be shaped, drawn out and cut with a chisel and hammer.

Once the desired shape is accomplished with a semi edge to it quickly quench it in the water but and then take out the blade so not to much heat is lost, let it slowly cool down, this will hopefully give some hardness and flexibility to the blade.

The easiest way to fix a hand guard is to cut a rebate up the blade slightly and make a slot in the guard. No easy task with leaf spring steel so plate steel may be a better option, just drill holes along where the slot wants to be and grind and file a-way until it fits the rebate on the sword. Cut a section on the bottom so that it can be rounded and threaded. It is hard to explain hopefully the picture shows what I mean. Drill a hole in both ends of the steel rod and thread them one to fit the sword and one to fit the bolt. It can be easer to weld the guard and rod to the sword but I prefer threading it so that I can disassemble it.

In a vice use the angel grinder to put an edge on the blade, and then refine on a bench grinder or water stone.

Clamp the blade in a wood clad vice so that it won’t bite the blade and with the drill sander bit take off the rusty looking surface, to reduce the time polishing use a finer sanding bit, once sanded polish with the drill polishing bit and abrasive wax.

Step 4: The Handel

A easy way of making a round griped handle is to use four layers of wood, cut the plank into four strips grain long ways chisel a semi circle on one side of two strips of wood so that when put together it will slip up the handle. Nearing the top it will have to be chiseled out to incorporate the bottom of the blade. Once done glue together the two strips with the other two and clamp them together.

Once dry put the handle on sword and cut off the bottom overhand keeping 0.5-1cm so when the bolt and washer is put on and done up it will hold the handle on hard. You can ether carve, plane or turn the handle in to the wanted shape. I used French polish on the handle to finish it but it is up to you. If you do decide to do this or something like this it’s nice to engrave the date and your name.

Step 5: Finished!

I hope this has been of some interest as it was to me! I know there will be a whole bunch of spelling mistakes and that there are perhaps better ways of doing some of the things I have mentioned but this is what I done and enjoyed it!

Tom K



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    357 Discussions


    3 years ago

    How much would it cost to build this forge?


    3 years ago

    is this for sale

    An Villain

    8 years ago on Step 3

    Listen to these guys, they are all correct, (though each favor different methods,) I agree with Bisquick on this, though my method of choice is better suited for swords of English design, as I've always found swords of Japanese design to be very weak unless forged by a master. While it appears you have used a combination of forging and stock removal to make this edged piece of metal, you first (from what I can gather from this Instructable,) cut it to general shape and then heated it and appeared to draw it out into its semi-final shape before grinding off the excess and edging it. This will give you what you would call an "edge", because that is what it is, you may not know it, but this edge (unless you REALLY lucked out) will either snap with a light (by true sword standards) blow or hold an edge for about 2 connecting slashes on a soft surface (fruit, cardboard, etc.) The proper method (for most straight double edged swords,) consists of either folding the steel (assuming it is already refined) into a billet (if different metals are to be used for the core and edge, then they are to be combined into a "sandwich" during the forming of the billet.) After the billet is formed then it is heated above Recrystallization temperature before being drawn out into the general shape of the blade (including the grind, tang, and if integral, the hilt.) After the forging of the blade, the blade is quenched, which prevents low temperature phase changes, as well as giving the metal the ability to hold an edge, with the trade off of making the metal very brittle (Water will give a harder sword with the small chance of distortion or microfissures, while oil will give a softer, more flexible blade, though the oils often tend to oxidize and form a sludge, lowering cooling efficiency even further.) After Quenching the sword is VERY hard but VERY brittle, causing it to snap if struck against something that will not give (rock, tree, ground, somebody else's sword,) this is why a sword is annealed afterwards, annealing involves reheating the metal above its recrystallization temperature again but this time allowing it to cool in the air until the smith decides to quench it, the earlier it is quenched, the harder and more brittle it will be, this is how it will always be with metal, what you gain in hardness (and therefore edge durability,) you lose in flexibility (and therefore the metal's resistance to breaking under stress.) After annealing comes the process of finishing the sword, this involves giving it a grip, pommel (if the design incorporated it,) finishing the hilt (also only if the design required it,) and polishing the blade. To polish the blade you will go over it with progressively finer grains of sandpaper until the desired finish is achieved, while you can go all the way down to a mirror finish if you desire, it is not recommended if you want to use your sword for anything other than a wall hanging as the finish will quickly dull and become scratched and it will be very "noticeable" shall we say if you ever get into a real combat situation (highly improbable but just in case.) After the blade is finished it must be sharpened, sharpening is done by grinding away material from where the edge is going to be, using a material that is harder than the surface being sharpened. This is usually followed by processes to polish the sharp surface to increase smoothness and to correct small mechanical deformations without regrinding. This is the accepted method for forging a sword from start to finish, it takes time to master and your first few "projects" most likely will not result in a perfect blade, but if you persevere, in time your efforts will be rewarded. Hope this helps.

    7 replies
    LazyHAn Villain

    Reply 3 years ago on Introduction

    I don't really agree with a lot of what you said. First of all, the steel type you are using determines a lot about how it has to be quenched. In addition, switching from one quenching medium to another does not have any negative effects on the blade as long as you beat the martensite "nose" of that blade steel. Even if the transformation to martensite isn't complete, as long as the blade is quenched quickly enough it will transform completely as it cools, meaning any hard spots will come from an error in the first quench, not in transferring to another quenching medium after the first quench. Also, you don't anneal after quenching the blade, you temper the blade. Annealing and tempering are similar, however neither is above the recrystallization temperature (critical temperature, of which there are actually three critical temperatures). Normalizing is above critical temperature, annealing is just below critical, and tempering is approximately around martensite start temperature, depending upon the steel and what temper/hardness you require (higher temperature=softer, lower temperature=harder). Annealing works by allowing the diffusion of carbon into carbide sheets or spheres as either pearlite or spheroidite, both of which are no good for a blade, but are softer and machineable. Diffusion and shear transformations happen below critical temperature, if you go above then the entire crystal structure (depending upon which critical temperature you reach) is dissolved and reforms depending upon the rate and extent of cooling. Once a blade is properly quenched, before tempering, the blade can be cooled to very low temperatures with either liquid nitrogen or dry ice in acetone depending upon the alloy to increase the overall physical characteristics of the steel, this happens by both diffusion and shear type transformation. The transformation is shear type as there will always be a tiny amount of retained austenite that will transform to martensite as you drop the temperature and diffusive because it allows the precipitation of really small carbides that increase toughness, neither of these transformations will cause hard spots like you describe.

    There is another type of transformation that may be better suited to a sword style of blade, that would be ausquenching (sometimes mistakenly termed austempering, considering that there is no tempering cycle in this heat treat method). The resulting crystalline formation is bainite, rather than the harder and brittle martensite. Bainite is formed when quenched to and held at a temperature below the martensite "nose" but (typically) above the martensite start temperature. The resulting structure does not require subsequent tempering and has a higher toughness for a given hardness when compared to a standard hardened and tempered steel of the same makeup. Though the steel does not require any subsequent tempering, there are some benefits to further thermal cycling of the proper temperatures to include but not limited to cryotreatment. Bainitic steel often has less internal stress and greater dimensional stability that martensite blades.

    I do apologize though, I normally would not have responded to such an old post but I felt the need to clarify some of the misinformation about heat treating that was posted.

    _Scratch_An Villain

    Reply 7 years ago on Introduction

    If you are quenching the metal, can you use liquid nitrogen, or maybe dry ice in 90% alcohol to quench it faster, or do you not want it quenched that fast?

    An Villain_Scratch_

    Reply 7 years ago on Introduction

    The faster the metal is quenched, the harder it will be, but the chance of distortion and microfissures increases exponentially the faster the metal is cooled.

    _Scratch_An Villain

    Reply 7 years ago on Introduction

    So you would probably be better off quenching it in water, then quickly moving to one of the colder things?

    An Villain_Scratch_

    Reply 7 years ago on Introduction

    The quenching medium is what ensures the evenness of the temper (the more efficient the quenching medium the less even the temper will be and vice-versa.) The hardness is determined by how long the metal is left out before quenching. Transferring quenching mediums is generally not a good idea as the metal often turns out with a variety of different properties (E.G. hard and brittle in one spot [metallic crystal structure is linear dendritic,] soft and flexible in another [metallic crystal structure is uniform/laminar,] or both very soft and very brittle [metallic crystal structure is amorphous AKA "metallic glass.")

    _Scratch_An Villain

    Reply 7 years ago on Introduction

    Ok. Thanks for answering my questions. Was gonna try and make a forge this summer like this and make a couple things.


    8 years ago on Step 1

    can i use aluminum instead of steel... i have a small fire pit and idont think it can get that hot

    2 replies
    Seth of choasthebomb745

    Reply 4 years ago

    Aluminum also has a bad habit of oxidizing extremely quickly, on my experience


    Reply 7 years ago on Introduction

    you could although not the best idea. because steel is both stronger and easier to work with if broken. aluminum dosent break but shatters.


    8 years ago on Step 3

    It is a good first try but there are a lot of improvements that could be made. The first improvement I would suggest is starting off with a lower carbon steel so you can get used to the folding process. Higher carbon steels tend to crack, especially if you are new to forging. The second suggestion i have is to quench it in oil. Oil does not transfer heat as quickly as water does and reduces the chance of your blade cracking. There are multiple steps to the quenching process that will allow you to create a better sword. Also full tang is the safe and professional way to make a sword and I fully suggest it. Good luck with your forging adventure!


    The katana is also made very differently than he made his sword. You can't just call any thin curved sword a katana :P


    true, but this sword was designed top imitate a katana. and also the word katana literally means sword, so any sword could be called a such ( though that would just be a stupid idea :P )