Traditional Japanese swords are usually highly regarded due to their quality and excellent craftsmanship. Most martial arts experts and modern swordsman collectors consider these Japanese swords as the best ones in the world. You should note that there are various reasons for this and one of them is because of the metal used in its structure.
The earliest Japanese swords were made up of steel. This was better than using bronze, but the swords were still prone to breakage. Because of this, the Japanese swordsmiths switched to Tamahagane which proved to be quite strong. This article discusses everything you should know about Tamahagane steel.
Understanding Tamahagane steel
Tamahagane steel is a special steel that was invented in the Japanese feudal era. This steel has higher carbon content than the standard steel, giving it unique qualities compared to other types of steel. Take note that a lot of carbon can make the blade fragile, so swordsmiths need to find the proper concentration.
It’s believed that this type of steel was invented by trial and error. Japanese cutlers usually try various ingredient mixtures to figure out which works best. Likewise, the swordsmiths realized that mixing iron sand with some phosphorus or sulfur and coal led to a high-quality metal that was suitable for making Japanese swords. Therefore, they started using high-carbon steel known as Tamahagane. A blade made of Tamahagane can hold more easily and can also bend under pressure rather than breaking.
How Tamahagane steel was made
As explained earlier, iron sand is a crucial component of the Tamahagane steel. But mining iron sand is a huge process and requires a delicate collecting process before smelting can begin. Most of the iron core in the earth comes from sedimentary rock deposits that were formed billions of years ago. A lot of these deposits can be found along coastlines and surrounding veins.
There is scarcity of iron ore in Japan because most of its coastal deposits are submerged below the waves around the archipelago. Unfortunately, deep sea mining is quite an expensive technology, both ecologically and financially, and was inaccessible to people centuries ago. Mining iron ore from the sea beds can still cost significant amounts of money, so it makes sense to import it from other countries. No wonder, Japan now imports most of its raw materials, such as iron.
Japan may have lacked enough iron ore deposits, but there was an abundance of volcanoes. Fortunately, there is a lot of iron sand in areas that have ancient rocks like basalt and granite. The Japanese swordsmiths used iron sand as a local alternative during that period before mass international commerce.
Iron sand is powdery and loose, making the extraction process cumbersome. Because the iron is usually heavier than basalt, quartz, and other minerals, they use water filtration to separate it. Miners used devices like sluice boxes or rocker boxes to catch iron particles. Such efforts usually required collective efforts of many ironworkers.
Today, there is a convenient and modern method that can be used to filter iron sand. In most cases, they use a magnet to attract the iron grains from the mixture. This method is easier and faster than utilizing water filters. When they collect the iron from the mixture, it is then smelted into Tamahagane. But the iron was not the only ingredient required to make the Tamahagane steel. It still needs to be mixed with a carbon source to offer strength and hardness to the final product.
The charcoal makes it a great carbon source and is quite easy to get compared to the iron sand. Therefore, they combine iron and charcoal and heat them to between 1,500 °F and 1,800 °F utilizing a special type of furnace known as a tatara.
The swordsmith can separate the different types of carbon steel, such as high-carbon steel and low-carbon steel. They can then forge the Tamahagane on alternating layers. Remember that during this process, the swordsmith can fold the steel at least 16 times. And, if the Tamahagane is not folded, then the heterogeneous distribution of carbon in metal can create weak points in the blade.
It’s crucial to remember that swordsmiths use several types of materials to make Tamahagane. For example, they sometimes use the hocho-tetsu to forge the core part of the sword while the high-carbon Tamahagane is combined with pig iron to create the outer layer of the sword.
In most cases, you can identify a great quality Tamahagane steel blade by checking its characteristic chrome or silver color. If you want to purchase a Japanese sword made from Tamahagane, you need to visit reputable sword suppliers. There are many authentic Japanese swords that are made up of Tamahagane steel on the market. Therefore, you can choose to ask the supplier to offer you an authentic Japanese sword or look at the characteristics of the blade to ensure that you are purchasing the right sword.
