Language: Japanese
Source: In common use

Description

Wariha-gitae / wariba-gitea (割刃鍛え) literally means "split blade forging". It refers to the fact that a split is made in the blade where the edge should come, and the edge is then inserted in the splice.

Somewhat similar to the hyoshigi-gitae construction, with the difference that the edge steel is spliced in instead of just forged on.

There is also a method called gyaku kōbuse-gitae (逆甲伏せ鍛え) or "reversed kōbuse" that achieves pretty much the same result by wrapping the softer back around the edge, with the edge exposed.

Notes
Markus Sesko; Encyclopedia of Japanese swords. Lulu Publishing. 2014. Page 519. (Available for purchase here.)

Further reading

Article: Construction methods of Japanese swords