An interesting opportunity to study the details and differences with two very similar kotanto in the same place at one time. The materials and construction are almost identical other than the blade steel and profile and a slight colour variation. The lighter coloured one was made from file steel and the darker one from 1965 Series 2a Land Rover leaf spring steel.
The main difference illustrated here is the approach in the carving of the mountings. One in a fairly straight minimalist style similar to traditional Japanese construction tools and the other with the subtle sculpting of a classical tanto or Japanese sword. One area where the classical tanto influence can be seen on both handles is the waisting effect when viewed from the edge side (second photo), but even this is more pronounced on the one than the other.
In terms of the blade profile, the file knife is based more on a classical tanto which narrows and sweeps elegantly up toward the tip over time. The Rover knife is inspired more by a koto katana which retains more width until the dramatic sweep up toward the tip at the last moment. The file knife has a peaked spine (iori-mune) while the Rover is square (kaku-mune), and both kotanto have a pronounced uchizori, downward curvature of the spine.
See the process of making these knives and the full specifications below:
Kominka Mountain Kotanto
Rover Mountain Kotanto
