Abstract: A convertible roll forming apparatus for forming flanges on a strip of material in which a roller assembly is supported on a support stand and disposed to move the strip material in a material feed direction. A pivotal support assembly supports a knuckle member for pressing against an edge portion of the strip material, the knuckle member cooperating with the support assemblies to progressively form the edge portion into a flange. The support assembly can be selectively disposed to form the edge portion in a first direction or in an opposing second direction. The strip material can be passed through serial passes of support assemblies and knuckle members to progressively form the flange. The roller assembly is supported for lateral expansion to accommodate various widths of strip material as required, and a lip forming section is provided to form a lip on the outer edge of the formed flange. Flange straightener assemblies are also provided to control the overbend.