Kiridashi are excellent little tools. They are single bevelled knives used instead of a pencil during carpentry, like a marking knife. Due to the single bevel, the rear flat section will register against a ruler exactly giving very precise lines. Having said all of this, it’s also great at cutting string or opening boxes.
The kiridashi is made from aogami 2 carbon steel and is 180mm long and 13mm width, with a cutting edge of 45mm.