For this topic, we will need to break things down into sub-topics. Metal working is extremely complex and I will try to reduce it into digestible portions. Why would we need to study metal working? Well, if you can’t purchase what you need, you will need to make it, and honestly, in a societal collapse, you won’t be buying much of anything anymore. So some basics will go a very long way. Much of what we present here is theory. You will learn very fast when you need/want to use this for yourself.
Forging
Forging is the process of heating metals up, then hammering them into the shape you want (up to 2,500 degrees). Forge welding is when you join 2 or more pieces of metals together by heating them up and hammering them together. A tack weld is a temporary weld used to create the initial joint between two pieces of metal. The hara Technique is when you fold multiple layers of metal over itself for strength. This is also called forge welding, you merge the layers using only heat and pressure. The plunge line is where the blade starts from the tang. It should be symmetrical on both sides. It is on the edge side where the edge starts and angles away from the tang on each side. Damascus steel is welded steel that produces a pattern of wave like formations in the blade. Liquid paper used in canister damascus must be dry before you add metal to the cannister. A canoe cannister is the same as a regular cannister, except it is open along its side instead of the end. A jelly roll is when the steel is tightly rolled for a unique Damascus appearance. Cold working the steel is when your work on steel at too cool a temperature that it can cause cracking to appear. A fuller is a rounded groove or slot on the blade, which is used to lighten the weapon as well as make it stronger. A hollow grind is a hollowed out section on the sides of the blade to make it lighter that leads toward the edge. A delamination is when 2 combined metals begin to come apart from fatigue often from repeated blows. Inclusions are pockets of air that can appear between layers while forge welding. Flux is a powder chemical that is added to help different metal types fuse together. Flux is any substance that promotes fluidity and to remove objectionable impurities in the form of slag. Limestone is commonly used for this purpose, as is silica, dolomite, lime, borax, and fluorite. W2 is very malleable steel with a carbon content between 1 and 1.5 percent. Sometimes people will use a baseball bat (wood) so they can hit the blade edge in order to flatten the backside without damaging the blade edge. An inclusion is a pocket of air between the layers of metal because they were not forge welded properly. Swing the hammer near your body so you don't tire quickly. Stand as ergonomically as possible do you don't get sore. You will only get about 6 to 8 hammer strikes before you need to put your metal back in the forge. Use the time wisely. If you have to stop, hold the metal in the air as contact with your anvil will steal heat away from your metal.
Quenching is the rapid cooling of the blade which makes the metal hard so it will hold its edge longer. You would normally do this in oil, not water. Thermocycling is the process of heating up your metal and cooling it down several times in order to make it stronger, AKA heat treating. Tempering is a heat treatment process that reduces brittleness. A differential quench is when you quench only the blade edge side to leave the spine softer so that it will absorb impacts. A hamon line is a visible line on the blade that is indicative of the harder steel of the blade from the softer steel of the center and top. Only medium and high carbon steel can be hardened. These are called hardened steel. Low carbon steel have higher melting points which make them hard to work with. A serrated edge helps keep that position of blade sharper longer during combat when you don’t have time to keep sharpening it. Grinding is the process of refining a blade by grinding off unwanted parts. Etching is the process of submerging the blade in an acid bath to bring out the detailed pattern in the metal. You can straighten a warped or bent blade using what is called the 3 pin method. You put the bent portion in the vice with 2 pins on one side and 1 more in between the other 2, but on the opposite side, then vice it. File testing is when a file will skate across a hardened blade smoothly. If it is not hard, it will not. Sometimes hardened metal can be softer than your file used for testing. In that case, it will still bite in but it is hard. A strop is a strip of leather used to sharpen razors and can be used to sharpen blades too. If you push too hard when you sharpen your knife on a grinding wheel or sandpaper belt, it will heat up the edge and you will lose the temper on your edge.
A bolster is a piece between the blade and the handle to provide extra strength and durability, much like the tsuba of a samurai sword. A lagnet is a thin strip of metal that runs down the handle to help secure the head in place (as on war hammers). If a drill bit squeals while you are drilling into your tang (handle portion of the metal), it means it is too hot (or broken/dull) and it will break if you don’t add oil or let it cool. A cold peen is when you hammer the end of your tang to mushroom it so it holds your handle without heat.
Sugar canes have similar consistency as human limbs for testing. Just saying.
Wear proper safety equipment. Don’t learn about safety by accident. Some injures are permanent. If you want to learn about eye protection, ask someone who only has one eye. Hearing protection is a sound investment. Breathing in metal dust can lead to siderosis, or welder’s lung. Leather aprons or the like are extremely helpful. Splashes of molten metal on your skin does not feel nice. Reaching in near a forge oven opening is also extremely hot. Gloves are handy. Forging a blade is definitely very loud, hot, and messy. And you might even get burned, sweat (a lot), and ruin some clothes. Be prepared.
You can forge completely without electricity, power tools, and gas, and you should know how in case you need to someday. But obviously, power tools and gas make things much, much, much easier. And I want to reiterate body mechanics. Workspace height is important and your swing is very important so you don’t get tired and sore. I have even seen a fire pit in the backyard used, filled with charcoal, and a tube and hair dryer. You can guess the temperature of your metal (if you need to) by sprinkling salt on it. Salt melts at 802°C.
Tools you will find good to have (I don’t want to say need) are an anvil, a forge (obviously), a hammer, tongs, safety equipment, a quench tank, and grinding tools.
The most plentiful element on earth is iron. The atoms in iron can be made stronger by introducing carbon atoms. They fill in the space between the iron atoms and prevent it from sliding. Carbon in different configurations will have different effects that could result in warping, blade rolling or chipping, breaking, or bending, or you can do it purposefully to get one part of your knife hard for strength, and another part soft for absorbing impacts. Adding carbon and other elements creates steel. Forging on a charcoal or coal forge will naturally impregnate iron with carbon, but there are other ways to do it, such as adding carbon from fingernail clippings or human hair, or carbon-based living mater by folding steel over the carbon-based material, or adding it to liquefied/melted iron, but now we are talking hard to do things. Rust is the result of iron atoms being removed from steel, and it will destroy your steel.
When steel is heated above 1350°F (732°C), the carbon and other alloys start to dissolve in the iron. The crystal structure of iron begins to change into a new structure called austenite. The level of austenite increases as the temperature rises. When the steel reaches 1450°F (788°C), all the crystal structures in the steel have become austenite where the grain formation is broken up and redistributed evenly. When you cool austenite steel slowly in still air, a structure called pearlite is formed. This form is a fine pearlite structure with small, evenly distributed carbides. A process called annealing is the same, except you slow the cooling process, which results in a softer metal. When you cool the steel very quickly, it is hardened and sometimes can be too hard and brittle. This can be avoided by not quenching steel that is glowing too red. You need to find the balance. Extremely high temperatures can actually burn the carbon out of the surface layer of steel. If this happens, it’s no longer high carbon steel and can’t be sharpened.
If you sharpen or shape a knife after you have hardened it, you could ruin the hardness. Watch for a gold colour, which means it is beginning to change, and blue, which means it has been softened too much. When you have more acute angles and less mass, your knife will have less drag and will cut easier. A thinner knife will cut better than a thicker one. A thinner
blade will have less drag and will pass through material easier. In losing thickness, you also lose overall blade durability. When grinding your angle, both sides make up the total when you are claiming the knife has such and such a degree. Scalpels and razors are 12°-17°. Hunting knives are 18 °-25°. Bushcraft knives are 26 °-30°. Samurai swords are 30°. Machetes and hatchets are 31 ° and up. If you grind the edge too thin, it will have a greater likelihood of warping or cracking during the quench. A good trick is to colour the edge with a marker so you can see what has been grinded. Start with a 50 grit and work up toward a thousand (2,000 for samurai swords). In between passes, dip it in water so you don’t ruin the blade and/or remove the temper. Don’t wear gloves. In this way, you can feel the temperature of the metal with your bare hands. You can use push sticks if you are near to grinding your skin, but that will take away your feel for temperature. Some knife makers use a jig to hold the knife in place at a designated angle and systematically grind away material. Use metal sanding paper such as aluminum oxide, and a little oil on your metal such as WD-40 will keep the sandpaper from wearing out too fast.
Hardening in water is usually frowned upon. It cools too quickly and can usually damage or crack your blade, but using water while shaping will keep it cool so it doesn’t turn blue. You probably should harden in oil. And agitate it so air bubbles don’t affect the hardening. You could preheat the oil for better control, but I personally don’t think that’s necessary. Salt water cools even faster than regular water.
Galvanized steel will release toxins when heated. Don’t use. You should aim for a steel between 0.6% and 1.6% carbon, if you can figure it out. The lower end is softer and easier to work with, and the higher end is harder and will perform better and hold an edge longer.
The numbering system of steel types (like using 1095 steel) is done in the following way: the first digit represents the primary alloy used, the second digit represent the secondary alloy used, and the last two digits represent the percentage of carbon (1095 being 0.95% carbon). 5160 is essentially 1060 plain carbon steel with added chromium. It contains between 0.56 percent and 0.64 percent carbon. Adding chromium helps rust from forming a little, and helps make the metal stronger. Another type of alloy steel, 6150 was originally used in coil springs, and has 0.48 percent to 0.53 percent carbon content and a small amount of added vanadium. It doesn’t hold an edge quite as well but it is much easier to work with. High carbon content of 52100 steel is between 0.98 percent to 1.10 percent. A2 is a tough and relatively hard steel with 0.95 percent to 1.05 percent carbon content. D2 steel has a 1.5 percent to 1.6 percent carbon content, so it is very hard with high 12 percent chromium. O-1 steel has a carbon content of 0.85 percent to 1.0 percent. Stainless steel has added chromium which adds a thin layer to the surface of the metal which prevents oxidative rust. One of the most commonly used metals is 440. It has a carbon content between 0.95% and 1.2% carbon making it hard, hard to forge, but holds a great edge and easy to sharpen. CPM154CM is a stainless alloy that has 1.05 percent carbon. S35VN is considered by many to be one of the best available knife steels. Damascus steel has recently been used to refer to layered steel that forms a pretty pattern, but true Damascus steel is was first made in Sri Lanka where typhoon winds would power their forges, then it was adapted in Syria where it was named after their capital. The steel was so hard, it could cut through other blades in battle. Tool steel is very hard and has varying degrees of carbon and is excellent for blade making.
When making handles, epoxy won’t bond properly to a surface if it is dirty or has any oils on it, so make sure your hands are clean as you’re handling it. Finish your handle by applying a coat of oil to the wood.
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