A plane used to shave the base of another plane. It is very important in planing that the base of the plane stock, known as the sole, daizura 台面, is maintained in good condition. The plane stock is made of hardwoods such as white oak or Japanese oak, quercus serrata, but the base does get worn away with use. It is used to shave flat the sole of a smoothing plane. The dainaoshiganna has a rather small-sized base, with the cutting blade fitted almost at right angles to the base. The reason for this is that the dainaoshiganna does not plane parallel to the wood fibers as most planes do, but shaves the sole at right angles to the fibers. Therefore, it is important to have the cutting blade held very firmly in place. The sole of a smoothing plane is not completely flat; the section between the head, daigashira 台頭, and the toe, daijiri 台尻, is usually shaved into a very slight concave curve.