The traditional Japanese Samurai sword has a revered place in Japanese culture and tradition. In the Medieval Ages, ancient Japanese swordsmiths would even perform elaborate purification ceremonies before they forged a new blade. The rituals were meant to summon beneficial spirits that would make the forging of the new katana swords favorable. Read on to find out japanese sword forging process.
Overview
Creating a new katana sword was an elaborate process that took several months using the traditional methods. It began with a construction of a unique model furnace known as “Tatara” where iron sand and charcoal would be burnt for three days and three nights. This would create steel and remove other impurities. The Japanese iron depots had more impurities and the blacksmiths of yore had to go through very elaborate processes to get rid of impurities.
The core of the steel generated is known as “Tamahagane” which translates to “steel jewel”. This is a porous iron and carbon block that still has lots of impurities. The remaining material consisting of carbon and a lower steel composition is used in the smoother parts of the blade. The remaining material can be modified further by adding parts of the “steel jewel”. It is suitable for japanese sword forging.
Of course, if you are not a certified blacksmith based in Japan, it is almost impossible to procure the Tamahagane steel with which you can forge a katana sword like the ancient Japanese blacksmiths. Outside Japan, swordsmiths mostly use steel from blast furnaces to make the sword.
Removing Impurities from the Tamahagane Steel
Once the forge had been heated, the tamahagane is put into the forge. The smith has to pump air into the forge to properly adjust the heat in order to smelt the tamahagane. This step is crucial for most japanese sword forging.
After it is heated, the tamahagane is pulled out of the forge and held on the anvil using a tong. This is then hammered flat. The hammering is done repeatedly and tapped in all directions. The tamahagane is hammered flat during which the impurities in the jewel steel will rise to the surface. They can subsequently be hammered out easily.
Pro Tip
To further get rid of the impurities, a process known as Mizu-ichi is done. Water is sprinkled underneath the tamahagane steel wafer and once again hammered out. This process leads to a peeling off the steel surface that further gets rid of the impurities. The steel is then quenched with water which cools it faster and makes it harder.
The wafers of the now harder tamahagane steel are broken into smaller pieces. The master blacksmith selects the best wafers for fashioning the steel. These are usually those that have 1.0% to 1.3% carbon which create a harder steel jacket.
Note
The tamahagane wafers are skillfully stacked on top of one another forming a steel block. The blocks are traditionally wrapped using a Japanese paper to stop them from falling over or spilling off. The paper-wrapped bundle is coated with black ashes that compensate for carbon loss in the heating process. The blacksmith then pours a clay and water mixture on the whole bundle. This not only distributes heat more evenly on the block but it also prevents carbon loss during heating process. The creates a uniform steel block.
Forging the Katana Sword
Next, the steel block is put in a forge and heated gradually to start the japanese sword forging process. It requires careful blacksmithing skill and intuition to heat this to the right forging temperature to avoid melting the steel. During the heating, the ash and paper wrappings will fall off. The smith must hence hammer down the tamahagane until the steel is uniform. When the steel layers have been compacted, the block of steel is wrapped once more and put in a forge. Repeat the process. The reheating maintains the plasticity. Bend and chisel the material on the anvil in order to create a blade shape.
Note
In forming the blade, the smith starts by hammering the steel into a rough shape of the sword. As the smith proceeds, they can lengthen the material as they proceed by drawing out. This is the point where the smith can fashion the blade to their liking.
The forging should proceed according to the pre-conceived shape. This requires expert techniques and an eye for swordsmithing. If done well, this stage will also reduce the number of times you will need to reheat the steel.
It is advisable to do the forging as fast possible so as to prevent carbon from leeching from the steel blade. Conserving the steel when blacksmithing is a crucial skill. At this stage, the blacksmith must also prevent the steel from cooling to prevent contamination from impurities. The height of a katana swordsmithing is the ability to produce a beautiful and organic jihada decoration on the blade of the sword.
The curvature of the katana sword will manifest itself later on as you harden the edge of the Japanese blade. One of the unique things about japanese sword forging is that it is not easy to preconceive how the curvature will turn out! What will determine the final shape and elegance of the katana sword is the skill and experience of the swordsmith.
As the shaping process of the katana sword comes to an end, you will begin to see the splendor of the sword emerge.
Finishing the Katana Sword
Once the blade has been hammered into shape, the next step is finishing the katana sword. To finish, begin with a rough filing of the sword. This japanese sword forging is vital because it will determine the frame of the blade.
After filing the blade, grind it using a whetstone. All the surface oil on the blade is then removed using an ash and water solution. The blade is then allowed to dry thoroughly.
Creating the hamon
The hamon refers to the pattern created on the katana blade during the final quenching. To accomplish this, you will use a clay mixture.
The adhesive clay used to create the hamon is made using a mixture of charcoal, pulverized wet stone as well as various other ingredients. This mixture used is kept a secret by master katana swordsmiths. The mixture is then uniformly applied on the rough ground switch. Paint clay on the blade to create a thin layer. After this has dried out, fire it as an essential part of japanese sword forging.
Hardening the Edge
In hardening, use small charcoal pieces that will prevent the clay coating from peeling off. The heat of the forge should be uniform. Carefully pass the sword into the forge and then pump air into the forge. Judging by the color changes, keep the sword temperature at between 755 and 780 degrees Celsius. The sword should be heated uniformly all through.
Quenching
After heating the sword to the right temperature, quench it suddenly in a trough of water. The dramatic cooling of the sword is important. For japanese sword forging, the faster that you cool the katana sword, the harder it will become.
Tempering
Heat the steel blade again to a temperature of about 400 degrees Fahrenheit (204.4 degrees Celsius). Temper the katana blade by quenching it again. Finally, allow the blade to cool to room temperature. This process will relieve the stress on the hardened edge of the blade. It also keeps the whole blade flexible and strong while at the same enhancing the curvature of the katana sword. The tempering balances the blade’s stiffness and flexibility.
Reveal the Hamon
Treat the blade further to get rid of the clay and reveal the hamon pattern. The hamon pattern will be clearly visible on the blade.
Work the Tang of the Blade
In Japanese, the blade’s tang is known as Nakago. Traditionally, blacksmiths carved out their signature marks here. Typical inscription marks on the tang include the following: –
1. Name of the swordsmith
2. Date of creation/forging
3. Name of the person who commissioned the sword
Drill a rivet hole into the tang. In Japanese, the rivet hole is known as mekugi-ana. This is where the bamboo mekugi pegs that will secure the blade to the handle (tsuka) will be inserted.
Finally, the sword is polished in order to bring out the intended hamon of the blacksmith. The polishing is also done to make the jihada appear more beautiful. It is the polisher that brings out the character of the sword and transforms it into a shining brilliance.
Making the Handle
The handle of the katana blade is made using a hardwood material. The handle of the sword should be long enough to enable it to be clasped with hands and also offer good balance when connecting the handle to the blade. The handle is then wrapped with ito and rayskin. Finally, add the two pegs, seppa, habaki and the guard to fix the sword.