hirahozo 平ほぞ

A true, square or rectangular tenon cut from a single block of wood. The top of the uncut part of the block forms the square shoulders around the base of the tenon. A short tenon is called tanhozo 短ほぞ, and a long one is called nagahozo 長ほぞ. These simple tenons fit into mortises *hozo-ana ほぞ穴, cut in the corners of ground sills, wall plates, non-supporting beams, and other structural beams. The long tenon is used at the corner of the ground sill to control shifting. An even better control for shifting is a rabbeted mortise and tenon, called *konehozo 小根ほぞ.