PURPOSE: To provide a wooden material jointing piece capable of increasing jointed strength, upon being driven into a wooden material, and ensuring high jointing workability.

CONSTITUTION: A wooden jointing piece shaped to (a) and (c) is used for a material having a coarse annual ring such as lauan and an Oregon pine, and the piece shaped to (b) and (d) for a material having a fine annual ring such as a white cedar and oak. Also, shapes (e), (f), (g) and (h) show cross sections of a body 1 and are roof type with a triangular material placed on a hollow rectangular form. A height of the body 1 is longer than length 1.05 times bottom length. The cross sections a' and c' of driving projections show the shape of a coarse material, and the sections b' and d' the shape of a fine material. When the driving projections are machined to right angles, a bending machining is implemented concurrently with a drawing process for extending the length of the body 1 by 1.30 to 1.10 times, thereby giving no increase in breadth. Furthermore, the constrained cutting or compression machining of the projections and the outside of the body 1, and right angle machining of the projections improve hardness and mechanical properties. Also, the projections enter a wooden material via a hollow structure and provide a large contact area, thereby improving jointed strength and strength against inclination in a vertical direction as well as in right and left directions.