Patent attributes
An HVAC duct section connection system is provided with first and second corner flanges, and at least one self-threading bolt. Both the first corner flange and the second corner flange include first and second legs. The first and second legs having an interior surface and an exterior surface. The exterior surface is disposed opposite the interior surface. The first and second corner flanges each have at least one fastener aperture extending between the interior and the exterior surfaces, the fastener aperture including an integrally formed truncated cone extending out from the exterior surface, wherein the truncated cone has an inner diameter. The self-threading bolt has a shank and a head, the shank having a threaded section with a thread diameter sized to engage the inner diameter of the truncated cone.
