At Fusahiro Shimojima's workshop, in the industrial city of Saitama, fires rage in small pits and an earthen floor absorbs the din of hammering. The 44-year-old Japanese swordsmith pounds the nascent blade of his newest creation, sending molten sparks flying majestically into air.

Yet, for all the heat, dust and sweat of metalworking, this studio is a sacred space.

Shimojima and his assistants are dressed all in white, a symbol of purity designed to keep negative forces at bay. A special rope known as a shimenawa -- used in the ancient rituals of Shintoism -- forms a perimeter around the space, serving to further protect the artisans from harmful energy.

"We worship god in our workshop," says Shimojima, who has been crafting samurai swords for the past 24 years. "Only then are we able to produce a sword ... not to be used as a weapon, but to be something of mental and spiritual significance."

Revered for their tensile strength and effectiveness in close combat, these curved swords, known as katanas, have been produced in Japan for centuries. They hold a unique place in the national imagination, having been used by samurais, nobles and martial artists alike.

But long after the abolition of the samurai class (and the outlawing of public weapon-carrying), the artisans' ancient production techniques live on. Shimojima specializes in a historic style of sword known as mamori katana -- a lucky charm that can protect its owner from illness and misfortune.

Shimojima may take a month to produce a single sword, with more complex additions able to take production time to more than a year. Credit: Detouur.com

"In today's society, there is not much use for a katana as a weapon," he says. "As a swordsmith, I find joy in creating a product that supports the mental and spiritual needs of the client, and one that can be handed down family generations for hundreds of years.

"Swords have been an integral part of Japanese tradition since the ancient times, and I believe a katana serves as an essential base for the traits and behaviors of Japanese people today."

Ancient techniques

Katanas were first produced over 1,000 years ago, and are distinguished by an upward-facing cutting edge that allows users to draw and strike in a single motion. Their role in Japanese society has changed dramatically since then, though the production process remains largely the same.

The blades are forged from tamahagane, a steel whose layers contain differing amounts of carbon. Shimojima painstakingly heats, softens and then folds the steel in order to remove impurities and even out the carbon content.

"A single layer becomes two layers, then two become four, four become eight and so on," he explains. "By folding 15 times, over 32,000 layers are produced. However, it does not mean that the more layers, the better. There's of course a limit, and if you exceed the limit you lose ... the strength required to serve as a sword."

Next, the sword is shaped -- although it begins completely straight. As the steel is hardened through a process of repeated heating and cooling, the differing densities in the blade's structure create its signature curve.

"In the space of 10 minutes, we heat up the blade to about 800 degrees centigrade and rapidly cool it down in water," Shimojima says. "It seems like a simple process. However... it's a matter of making a split-second judgment.

"One mistake can often lead to a total failure -- a fatal mistake," he adds.

Shimojima's traditional techniques differ little from those used by Japanese swordsmiths for centuries. Credit: Detouur.com

The resulting blade should demonstrate a balance of strength, flexibility and durability. Shimojima's workshop may take a month to produce a single sword, with more complex additions (like mountings and hand guards) sometimes taking production time to over a year.

Tradition in decline

Acquiring mastery is laborious, and apprenticeships take years to complete and are often unpaid.

Sworsmiths harden steel through a process of repeated heating and cooling. Credit: Detouur.com

For Shimojima, it was the swords' timeless appeal that first attracted him when, as a junior high school student, he came across an 800-year-old katana at the Tokyo National Museum. Struck by its flawlessness, it was an encounter that led him to peruse a career in sword making.

"Throughout its history, (the craft) has been passed down over generations without ever changing its shape, its stance, its values or its meaning," he says.

"The fact that (old katanas) have not been covered in rust, nor have they begun to decay, proves their quality. Therefore, we must spare no effort, even for the (swords') unnoticeable parts.

"I do not believe that Japanese swords themselves will disappear from this world," he adds. "Good-quality katanas from the old days will always survive and be remembered."

The swords must undergo an extensive polishing process that can take weeks to complete. Credit: Detouur.com

Modern production techniques pose a further threat to the profession, allowing manufacturers to make similar items quickly and inexpensively -- in neighboring China, especially. They are, however, no substitute for the real thing.

"Every step of its production process, as well as the reasons behind it, are all for its practical use, and its beauty comes as a result of that," Shimojima says of his traditional techniques. "I believe the beauty of a Japanese katana lies within its simplicity -- its aesthetics without any unnecessary elements.

"Functional, yet with a hidden elegance."