Internally threaded barrel-shaped fasteners integrally formed with a flat base, which has prong-type projections extending perpendicular from the base aside the barrel.

3-Prong: Used for fastening metal to products made of wood, particle board or plastic. The 3-prong style is used in harder materials to minimize splitting of the mating surface.
4-Prong: Four prong tee-nuts can be used in hard or soft woods.