Many expert swordsmiths and enthusiasts consider Tamahagane the best steel for making the legendary katana.Turning ordinary-looking sand into a deadly blade only adds to the steel’s mysticism. But is Tamahagane the best steel for a katana? Or, are there cold, hard truths we must learn behind this “magical” steel?
Please continue reading to learn more about Tamahagane steel, its production, types of Tamahagane blades, and why it remains a favorite of Japanese master swordsmiths (Katana-kaji).
What is Tamahagane Steel?
Tamahagane features two Japanese terms, “tama” and “hagane,” roughly translating to “precious steel.” The etymology underscores Tamahagane’s significance in handcrafting traditional Japanese swords like the katana. It’s just one of the many secrets of Tamahagane steel.
Although Tamahagane steel is the preferred material for making blades by swordsmiths, sourcing its principal component – the “satetsu” (iron sand) – isn’t easy. Historically, this raw material is only found in modern-day Shimane Prefecture in southern Japan.
Satetsulooks like beach sand, except it’s black and coarse. It has iron particles and traces of vanadium, titanium, and other metallurgical elements. Impurities determine whether Satetsuis high-grade (Masa satetsu) or low-grade (Akamesatetsu). Seasoned Japanese swordsmiths only use Masa satetsuto produce the finest Tamahagane steel for the best katana in the land.
A bowl of satetsu or iron sand. Credit: Richard C. Shaffer
Most of Japan’s iron ore deposits are in sedimentary rocks beneath the waves. Although present-day Japan could mine these ores, the undertaking is costly and can impact the archipelago’s ecology. Hence, most Tamahagane katana-makers import iron ore.
It’s also unlikely that early Tamahagane swordsmiths would mine iron ores deep in the sea. Thankfully, Japan is rich in volcanoes, allowing early Katana-kanjis to source satetsufrom volcanic rocks. Erosion across thousands of years wore down basalt and granite into powdery and loose volcanic grains.
Today, some Japanese still scour beaches, streams, and riverbeds for satetsu, allowing master swordsmiths to continue traditional Tamahagane steel production and katana-making.
From Sand to Blade: The Tamahagane Journey to Katana
Converting satetsuto Tamahagane steel is labor-intensive. Katana-kajis, who still adhere to traditional sword-making practices, often require three days and nights to produce Tamahagane steel.
Experts say 12 tons of charcoal and 2.5 tons of satetsuwill yield 2.5 tons of Tamahagane. Unfortunately, the entire production process only produces about 2,000 pounds of high-quality Tamahagane steel.
Here’s how expert katana-makers transform iron sand into Japan’s legendary sword.
- Iron Sand Collection and Processing
Collecting satetsufrom riverbeds, beaches, creeks, and streams rich in volcanic grains is like gold panning. Workers scoop satetsu-rich sand-filled water and pass it through a mesh in sluice or rocker boxes. Separating iron from minerals such as basalt and quartz is easy because the former is heavier.
Unfortunately, such an undertaking is labor-intensive. Teams must scour large areas to filter iron grains. The project can take days or weeks to complete a ton of high-grade satetsu. A more efficient method of collecting satetsuinvolves using magnets.
A worker dipping a magnet-tipped rod into a bucket full of satetsu. Credit: Voyapon.
- Smelting
Satetsu alone will not produce Tamahagane steel. It requires another “ingredient,” albeit a more readily-available material than iron sand. Although iron is strong and hard, charcoal (the principal carbon source) can increase these attributes.
One can think of satetsuas the flour in a batter. Meanwhile, charcoal is the binder. Combining satetsu(the flour) and charcoal (the binder) will create a stronger and more formidable Tamahagane steel (the dough).
Smelting iron sand and charcoal require a Tatara– a traditional clay tub-type furnace. Workers create a four-foot-wide, four-foot-tall, and 12-foot-long clay tub and allow it to dry.
Once dried, workers use a charcoal fire to heat the Tatarato about 1,500 to 1,800 degrees Fahrenheit or 815 to 1,000 degrees Celsius. Some would raise the furnace temperature to 2,500 degrees Fahrenheit or 1,400 degrees Celsius. It’s crucial to keep the iron sand-charcoal mixture from melting to ensure the ideal carbon composition.
Workers shovel iron sand into the Tataraclay tub every ten minutes. They also add charcoal (sumi) in between and mix the two materials.
Each iron-carbon layer sinks to the Tatara’sbottom every hour, allowing workers to continue adding satetsuand sumiat the top. Workers perform this heating, mixing, and folding process for 72 hours or three days.
Each ton of iron sand processed yields 100 pounds of Tamahagane steel. It’s a sleepless, exhausting, and strenuous steel-production method that amplifies Tamahagane steel’s near-mythical status.
Workers at smelting at a tatara. Credit: Japan Times
- Separating High-quality Tamahagane
No Tatarasurvives after a single Tamahagane steel production. Workers must break the clay tub to access the Tamahagane at the bottom. The resulting Tamahagane steel block cannot go to a master swordsmith to turn into a katana unless theMurageseparates the high-grade (high-carbon) steel from low-grade sections.
The Murage inspects the Tamahagone steel block for impurities and determines the correct proportion of Akameand Masa satetsu. Too much carbon, and the katana might be brittle. Too little carbon, and the katana will turn soft.
Low-grade Tamahagane steel is gray and soft because it retains more of the satetsu’sblackish color. Meanwhile, high-grade Tamahagane has a lustrous, almost silvery appearance and is hard. Tamahagane steel on the Tatara’ssides contain the best material for turning into Tamahagane katana because proximity to heat facilitates more efficient oxidation.
The Muragecleaves the Tamahagane steel block’s high-grade chunks and ships them to master swordsmiths and tradespeople who forge tools.
- Slag Removal
A master swordsmith heats the Tamahagane chunks and executes a cycle of hammering, folding, and heating to remove as many impurities as possible. Striking the hot Tamahagane steel sends sparks into the air, proof of air bubbles or impurities from the material.
The katana-kajiinspects the Tamahagane steel wafers and analyzes their purity, leaving behind only the best Tamahagane steel for katana. As the swordsmith continues pounding the metal bar, he continuously judges the iron-carbon proportion.
- Blade Forging
The swordsmith packs the Tamahagane steel wafers on a smelting stick and covers them with washi paper. To guarantee adhesion, the swordsmith covers the wafers with a clay slurry before heating them in a furnace at 2,500 degrees Fahrenheit or 1,371 degrees Celsius.
As the steel wafers soften, they become more malleable. The kitana-kajihammers the semi-molten chunk into a long metal bar, ensuring equal carbon distribution throughout the Tamahagane steel. The swordsmith folds the steel and continue hammering into the katana blade.
During blade forging, the swordsmith inserts heated lower-grade Tamahagane steel (low-carbon content) into the steel. This action allows the swordsmith to produce a katana with a soft steel core (for improved durability and enhanced tensile strength) and a hard exterior (for a sharp and deadly edge).
- Coating
With the Tamahagane steel now resembling a katana blade, the swordsmith coats it with a special clay paste to protect it during the final hardening. One side of the blade has a thicker clay coat, leaving the blade’s leading front edge as thin and sharp as possible.
The katana-kanji inspects his work and places the clay-covered blade into a hot furnace for the final heating. Ideally, the temperature should not exceed 1,500 degrees Fahrenheit or 815 degrees Celsius to avoid ruining the precious Tamagahane steel. Otherwise, it’s back to square one.
- Quenching
This step requires the katana-kanji to act quickly in submerging the hot Tamahagane steel into the water to cool and harden the steel. Because the blade’s front edge is lightly covered with a special clay, it hardens faster than the back side. It also packs carbon molecules more tightly, ensuring an extraordinarily sharp edge.
Meanwhile, the blade’s backside (covered with thick clay) hardens slowly, improving its tensile strength and durability. The variable carbon structure and differential heat application give the katana blade its emblematic light-and-dark wavelike pattern (hamon) along its length.
- Polishing
With the Tamahagane blade forged, shaped, and hardened, the swordsmith gives it to a master polisher to give the blade its characteristic luster. Polishing a Tamahagane blade is time consuming, with experts taking at least three weeks of water stone polishing to give the katana its iconic look.
A Tamahagane katana ready for polishing and finishing. Credit: ANA Cool Japan
- Accessorizing and Finishing
Another craftsperson handles the Tamahaganekatana’s finishing requirements. They add a tsuka(the handle), a tsuba(the blade guard), a saya(the scabbard), and other adornments.
It’s worth noting that it takes 15 to 18 months to complete a single Tamahagane katana, from satetsucollection and processing to the final presentation of the fabled Japanese sword.
Tamahagane Steel Composition in Katana
The katana is a single-edged, slightly-curved, and slender blade with am exceptionally long handle for a two-handed grip. Its blade ranges from 23.62 to 31.5 inches or 60 to 80 centimeters. A finished katana weighs about 2.2 pounds or a kilogram.
Given the katana blade’s dimensions, one cannot help but wonder how much Tamahagane steel goes into each katana.
Most people find it unbelievable that a single 2.2-pound katana starts from 22 to 44 pounds or 10 to 20 kilograms of pure Tamagahane steel. Although there are variations, the differences are nearly negligible.
But why? How can that much Tamahagane steel produce a katana of only about a tenth of its weight?
The unusually long forging process accounts for this weight variance between raw Tamahagane steel and a completed katana. Swordsmiths heat, hammer, and fold the sword metal many times. These processes remove impurities and turn most of the Tamahagane steel into iron oxide.
Is Tamahagane the Best Steel for a Katana?
This question is tricky. On one side, Tamahagane steel is synonymous with the katana, the world’s most famous sword. The Japanese frown upon Katanas that use steel other than Tamahagane. Katanas follow the Samurai and its many legends, including ancient bladesmithing methods and materials. Unsurprisingly, katana-kanjis must undergo rigorous inspections and adhere to strict laws before they can create a traditional katana.
On the other hand, real-world modern tests demystify Tamahagane steel’s multi-fold construction. Legends say Tamahagane’s strength lies in its folding process, with swordsmiths bending the soft and hot steel more than 1,000 times. Unfortunately, science says folding the Tamahagane steel four times cannot increase its tensile strength, let alone a thousand.
Tamahagane steel might not be the strongest for a katana, but it remains the best. And here’s why.
- Katana IS Tamahagane
A katana symbolizes Japan’s rich culture, especially the Samurai culture, with ethical behavior, discipline, and respect at the very core. As mentioned, a katana isn’t a katana if it’s not Tamahagane steel.
- Tamahagane Venerates Japan’s Culture
Tamahagane steel production underscores Japan’s rich heritage of fine swordmaking. Master swordsmiths don’t learn the craft from books and internet sources. Their knowledge is a wealth of experiences handed down across generations. One can say traditional Tamahagane katana-making is a dying breed, with fewer 21st-century generations willing to embrace the ancient art of katana-making.
- Tamahagane Steel Embodies Traditional Craftsmanship
A Tamahagane katana doesn’t only symbolize Japan’s rich heritage. It also venerates Japanese craftsmanship. Japanese swordsmiths spend months producing a single Tamahagane katana, underscoring their dedication and commitment to perfection. No Tamahagane katana will leave a shop blemished or incomplete.
- Tamahagane is Symbolic and Beautiful
No modern sword-making technology can match a Tamahaganekatana’s aesthetics and symbolism. The hamonis only possible with the swordsmith’s meticulous attention to packing the special clay. Without it, the katana will not have its characteristic wavy pattern in light and dark shades.
- A Dependable Steel
Tamahagane steel might not be the world’s strongest, but its razor-sharp edge can still cut through most objects. It’s also worth pointing out that Tamahagane is high-carbon steel, making it impervious to corrosion. Moreover, nothing beats a Tamahagane katana as a work of art.
How Much Does a Tamahagane Katana Cost?
Making Tamahagane steel from raw satetsuis a labor-intensive and tedious project. Forging the Tamahagane steel into the iconic katana or other Japanese blades is equally challenging. Although machines are available for creating other swords, Japanese katana-makers only rely on age-old traditional methods and practices.
Unsurprisingly, a single Tamahagane katana can take up to two years to produce from sourcing the much-coveted satetsuraw materials. And everyone involved in the production relies on their hands and years of experience.
So, don’t be surprised to see an authentic Japanese katana with expertly-forged Tamahagane steel crafted by a Japanese-certified katana kanji fetch a handsome price. The starting price tag for these swords is $5,000 and can easily skyrocket to $12,000.
The Bottom Line
Tamahagane steel isn’t the strongest for any sword, let alone a katana. However, this sword steel remains the best for an authentic Japanese katana. It symbolizes the sword’s and the people’s rich cultural heritage and the swordsmith’s attention to detail and commitment to excellence and perfection. No other steel can be as emblematic as Tamahagane for the revered katana.
