If you love bonsai trees then a bonsai knife (also called a jinshari or ureshi) is an essential tool in your collection. Kiridashi knives are a very versatile tool that are used by carpenters as marking and carving knives, by leather workers for detailed cuts and paring, by horticulturists to prune and detail bonsai trees, and by bonsai enthusiasts to mimic nature in the practice of creating shari, jin and uro in their plants.
They’re simple, lightweight and incredibly durable. Originally used by Japanese children as pencil sharpeners and in art classes, they’re now one of the most popular EDC knives on the planet. They’re often found in peoples’ pockets or handbags for use as a utility knife; cutting ropes, opening letters and boxes, or whittling on a camping trip.
A kiridashi is basically a single bevel blade that’s been ground into a very narrow cutting edge. They can be inserted into bamboo scabbards, wrapped with cord for a grip, or simply carried as-is and used as needed. Kiridashi are typically crafted from Yasugi Shirogami or Yasugi Aogami carbon steels, but they can also be made with 1095 or W1 carbon steels.
The most important qualities to consider when purchasing a kiridashi are its hardness, edge retention and corrosion resistance. These are all factors that affect a knife’s ability to remain sharp and cut deeply.
Kiridashi are relatively easy to maintain and should be regularly disinfected after each use to prevent the spread of fungus or other bacteria from one plant to another. They should also be kept in a dry location when not in use to avoid rusting. A whetstone can be used to hone the blade and, when necessary, a professional knife sharpener can be consulted to restore the original cutting edge.