Hada – Katana Grain
Japanese swords are made from folded steel. These lines are visible and known in Japan as Hada. This lines will depend on how many times the blade was folded. Japanese sword enthusiasts know the importance of Hada Katana on the sword. A well-forged Katana Hada shows the mastery of the swordsmith of the thorough knowledge and control over the skills. Producing the Hada begins in the Shitaji stage and onto the Shiage stage. In this process Hato and Jito stones are used. These are similar stones like those of the Uchigomori stones. Some swordsmiths continue to use these stones in the Tsuya process. The stones commonly use for the Tsuya process are Hazuya and Jizuya. In the case of Jizuya this captures the beauty of the steel. It is absolutely necessary to choose the proper stones for each sword.
Distinguishing Visible Grain
Most handmade Japanese swords have a visible grain in the blade steel. The obvious marks are left in the sword depending on the method of forging used on it. However, for new collectors Hada is hard to recognize. There are actually old blades that have no visible Katana Hada. This does not mean that the blade is not handmade. If truth be told, grain does not reveal the age of the blade. Some of the World War II era swords show prominent hada. It would be a bad idea to polish the blade just to reveal the Katana Hada. Leave this to the professional swordsmiths. Polishing this without proper skills can reduce the blades value to zero. Newcomers are confused about how many times the Japanese blades are folded and the number of layers that it has.
Different Kinds of Katana Hada
Ayasugi Hada. The strength of the hammer blows are controlled during the forging process but, basically this follows the same Masame Hada
Itame Hada. Produced by folding the billet in alternating directions during the forging process
Konuka Hada. This means rice bran. This kind of swords are typically produce and use in the Hizen province
Masame Hada. This is produce when steel billet is repeatedly folded in the same direction. The lines seen on the blades shows stacks of layers produce during the forging process
Mokume Hada. This is based on Itame hada using a different hammer blow to produce whorls
Muji Hada. This has a very tight pattern that is hard to discern especially for beginners. This is referred to as Jihada without a grain pattern but, the hada is there. It takes a great swordsmith to produce this kind of hada
Nashiji Hada. This is referred to as Pear Skin
It is the forging and folding process that produces a wood grain pattern on the blade. A common myth told and retold is that of Japanese swords that are folded a thousand times. However, in truth, it takes about 10 to 15 times fold depending on the methods used by the swordsmith. With every fold, the strength of the sword increases. For those who are buying Nihonto check out the blade. If there is an acid etched hamon and bad hada, this is a dead giveaway. This is also a sign of bad hada.