2. The Myth of the Samurai Super Sword
Katanas inspired many legends. They were reportedly forged by master sword smiths who hammered and folded the blade over a thousand times. They were also rumored to be so sharp that they cut through machine guns in WWII. Unfortunately, that is a pure myth. In real life, back in their heyday, katanas, coupled with a smaller sword, were thrust, sharp edge facing upwards, through the bearer’s obi – a sash wrapped tightly around the samurai’s waist. The configuration was known as daisho, and it identified the wearer as a samurai – the only people authorized to tote paired swords.
Katanas worn in the daisho style facilitated a speedy draw, ideally allowing samurai to draw and cut down opponents in a single fluid motion. An entire martial art, Iaido, was dedicated to the speedy retrieval of katanas from their scabbards. Katanas are made from tamahagane steel. It is produced by traditional Japanese smelting processes that result in layered steels with varied carbon concentrations that are welded, folded, and hammered out to reduce impurities. A katana needs a sharp and hard edge. However, steel that is hard enough for a sharp edge is brittle, while softer steel that is not brittle will not take and retain a sharp edge. That posed a problem for sword smiths.