What is Nokozukuri in Japanese Katana terminology?

"Nokozukuri" (鋸造り), also known as ""Nokobazukuri"" (鋸刃造り), refers to a type of sword construction where the ridge (Mune) of the sword is shaped like a saw (Nokogiri).

These swords were not only used as weapons but were also used on ships to cut ship equipment such as mooring ropes. They were known for being produced in Kaifu District, Awa Province (currently near Kaiyo Town, Kaifu District, Tokushima Prefecture), and were characterized as ""Kaifu Swords"" (海部刀).

The group of swordsmiths who worked in Kaifu District were known as ""Kaifu Kaji"" (海部鍛冶), and they flourished from the Kamakura period to the Edo period. During the Muromachi period, about 60 swordsmiths were active along the Kaifu River. In the Edo period, they became renowned as the retained swordsmiths of the Tokushima feudal lord, the Hachisuka family.

The Kaifu swords, which were made with a single-edged blade construction, were known for their excellent sharpness. They were said to have been highly valued for various purposes, such as hunting swords and for constructing fortifications."