What is Hirazukuri in Japanese Katana terminology?

The term ""Hirazukuri"" (平造り, ひらづくり), also known as ""Itazukuri"", refers to a specific style of Japanese sword construction. This style is characterized by the absence of a ridge (Shinogi) on the flat side (Hira) of the sword, resulting in a flat surface.

This style of construction is commonly seen in ancient swords (Jokoto), particularly those made before the Heian period. Many of the Tachi (a type of Japanese sword) made during this time were of the Hirazukuri style. After the Heian period, this style was most commonly used in the construction of short swords (Tanto), followed by Wakizashi (a type of short sword), but it is rarely seen in Katana (a type of long sword).

The Hirazukuri style is said to have excellent sharpness due to its sharp blade tip, making it superior in terms of cutting ability."