Japanese Sword Making

1. A chunk of high-carbon steel is sandwiched together with a chunk of slightly softer high-carbon steel. The steel pieces are pounded together, then folded over onto each other over and over until only one slab of steel emerges.
   
   
2. The steel is then heated, pounded, heated, and pounded until the steel becomes long and thin (the desired curvature is simply hammered out during this thinning process). The ingenious part about this is that the combination of hard and soft steel being pressed together creates a laminated sandwich effect of thousands and sometimes millions of layers. This is important because this lamination effect strengthens the blade (hard steel) while simultaneously keeping it soft enough (soft steel) not to break on impact. If the sword is too hard, the sword becomes brittle and can break when clashing with other swords. If the sword is too soft, the sword will not hold a sharp edge for very long. It will dull rapidly, and that could mean death on the battlefield. The balance has to be just right.
   
   
3. Now comes the all important creation of the sword edge. Once the sword is pounded into the desired shape, the sword maker coats the spine edge of the blade (mune) with clay while leaving the cutting edge exposed (or sometimes, the entire blade is covered with the spine having a thicker coating of clay than the edge). The blade is then heated up again then instantly cooled in water (sometimes oil). This is where the importance of the clay comes in - the instant the blade is cooling, the uncovered cutting edge portion of the blade becomes very hard because it's being cooled very rapidly. The back edge that is covered in clay cools at a much slower rate preventing it from becoming as hard as the cutting edge. The clay is cleaned off, and what remains is an edge that is hard enough to hold a sharp edge (because it's got hard steel folded in and around it), but soft enough to resist direct impact (the softer metal of the spine makes it slightly springy). Pretty smart, eh? A nice side effect of the claying process is what's called the hamon. The Hamon is that wavy pattern along the edge of the blade. Japanese swords that have not been folded or forged may have a fake hamon to give the illusion of authenticity (click here to find out more about authentic Samurai swords).
   
   
4. The bare blade is then sharpened on a wet stone by hand (real Samurai swords are never sharpened on grind wheels). The tip is also shaped and sharpened to perfection.
   
   
5. The tsuka (handle) is then made out of two, carved, halves of wood. They are wrapped in ray skin (or leather, or synthetic ray skin), then wrapped with silk or cotton cord in the desired grip pattern.
   
   
6. The hand guard (tsuba) and fittings around it are shaped then wedged onto the tang (the bare steel handle) of the blade. The fully wrapped tsuka is then wedged onto the tang. A wood or brass pin is hammered into a pre-drilled hole that goes through the tsuka and the tang. This locks the blade into place.
   
   
7. The scabbard is then created by two halves of wood fixed together then laquored and/or painted.
   
   
8. Finally, your sword is polished and is ready to cut!