This is a large karimata shaped yanone often referred to as a “rope cutter”. The primary function, however, is as a flesh cutter used in battle and for large game. The early karimata are very thin and it’s easy to see how well they can cut. The later karimata from the middle to late Edo period tend to be thicker and have ridge lines. Even though they can still cut, they would not be as effective as the older shapes.
This karimata yanone is mumei and dates from the middle Edo period. The hamon where visible is suguha and the hada is masame along the blade. There is a ware between the bottom of the notch and the shoulder, but it does not detract in any way.
The nakago is 10-5/8 inches (17cm) long, the blade is 3-1/8 inches (7.9cm) long by 2-1/2 inches (6.4cm) wide.