Abstract: An assembly piece for connecting metallic carpentry sections includes an angle piece having two parallel quadrants and an arced middle portion. A flat angle bar defined by two perpendicular portions is attached between the quadrants. A respective perpendicular portion extends from between the quadrants parallel to a respective side of the quadrants. Each perpendicular portion has two radially directed arms separated by a radial space opening away from the other perpendicular portion. With this construction, the two arms of each perpendicular portion are received in suitably provided radial runners of the carpentry section. Each arm also includes an aperture therein so that a screw passing through the carpentry section is received therein to hold the carpentry section to the angled piece. A flat bar extending perpendicular from one quadrant and having an aperture therein is also preferably provided in order to attach another carpentry section to the angled piece.