Traditional Japanese katanas are not typically made of Damascus steel. The historical Japanese swordmaking tradition primarily involves the use of a specific type of steel known as tamahagane, which is made through a complex smelting process using iron sand (satetsu) and charcoal. This traditional steel-making technique produces a steel with specific properties desired for Japanese swords.

Tamahagane steel has a distinctive grain structure and composition that contributes to the unique characteristics of Japanese swords. The blade is typically made from a single piece of tamahagane steel, without the layered construction seen in Damascus steel.

While traditional Japanese katanas are not made from Damascus steel, modern interpretations and variations of the katana may incorporate Damascus steel construction for aesthetic purposes. Some modern swordsmiths and artisans create "Damascus-style" katanas using layered steel construction similar to Damascus steel, but these are not considered traditional Japanese katanas.

It's important to differentiate between traditional Japanese katana made with tamahagane steel and modern interpretations or variations that may incorporate Damascus steel. If you are specifically looking for a traditional Japanese katana, it's recommended to seek out experienced swordsmiths or reputable dealers specializing in traditional Japanese swordmaking techniques.