Tetrahedral joint for furniture supports

A tetrahedral joint comprising

• three flat pieces having equal thicknesses each defined by a flat surface, said three flat pieces each having a straight edge extending along an axis, said straight edge being perpendicular to said flat surface,
• each of said three flat pieces respectively having an open-ended slot cut along an axis into said straight edge through said flat surface, said open-ended slots forming miter angles of less than 90.degree. respectively with respect to said edge of each of said three flat pieces,
• each of said open-ended slots having uniform widths generally equal to said thickness of said three flat pieces,
• said open-ended slots being cut through said flat pieces at tilt angles in the range of 90.degree. or less with respect to said flat face,
• each of said three flat pieces being inserted across the width of the open-ended slot of another one of said three flat pieces and into the slot of the third piece to interconnect said three flat pieces to form a joint, said axis of each of said three open-ended slots intersecting each other at a common point when each three pieces are assembled;
• and
• said miter angle and said tilt angle of said open-ended slot of said third piece establishing the direction of said plane of said flat surface of each said flat piece being inserted.